Hot-Spot Analysis and Scenario-Driven Life Cycle Assessment of Authenticated Greek PDO “Avgotaracho Mesolongiou”

Abstract

Food systems account for one third of greenhouse gas emissions while fish production is assigned 4% of total anthropogenic emissions as well as other environmental implications. The Greek fishery industry is a very promising and upcoming sector with renowned products such as “Avgotaracho Mesolongiou”, the Greek bottarga, which is a product of designated origin (PDO) with cultural and economic significance but unexplored environmental impacts. The aim of the study is to depict the environmental hot-spots of “Avgotaracho Mesolongiou” production using the life cycle analysis (LCA) methodology with the help of SimaPro v3.5 software and the Ecoinvent database v3.9. “Avgotaracho Mesolongiou” supply chain is divided into the fish extraction, roe processing and transport, and retail stages, while the inventory of each stage is filled with data depicted from producers via a questionnaire and findings from the literature. The hot-spot analysis of Avgotaracho Mesolongiou exhibited high human carcinogenic toxicity, and marine and freshwater ecotoxicity impacts that account for more than 90% of total normalized scores. More specifically, the use of metallic traps in the fish-catching facilities presented the highest contribution among the inputs and was responsible for more than 70% of total normalized scores. Furthermore, the uncontrolled treatment processes of waste streams are attributed 6% of total normalized scores. More specifically, waste wood open-burning accounts for 10% of human carcinogenic toxicity while disposal of wastewater was responsible for 25% of freshwater eutrophication. Moreover, a scenario-driven LCA was conducted to compare the existing waste treatment meth+ods to a proposed improved waste management (IWM) scenario. The implementation of controlled treatment processes resulted in a decrease in human carcinogenic toxicity and freshwater eutrophication impact by 8% and 26%, respectively. The outcome was proven to be robust in respect to the affected impact categories while the fish extraction remains the most impactful stage of the supply chain when subjected to a sensitivity analysis.

1. Introduction

The observed climate change (CC) is causing the global surface temperature to increase, provoking changes in the earth’s ecosystem. According to the latest report of the Intergovernmental Panel on Climate Change (IPCC), the accelerating way that CC is upscaling is promoted by human activities [1]. Greenhouse gas (GHG) emissions play a crucial role in the impact of CC. Almost one third of global anthropogenic GHG emissions are attributed to the food chain [2]. Reversely, CC affects food production in various ways and adaptation measures are necessary [3]. Other important factors that impose pressure on the ecosystem are population growth, food consumption patterns, and food production increase. Consequently, the Earth is facing a triple crisis, not only with CC but also biodiversity loss and pollution [4]. Nowadays, the reported biodiversity loss rates are the highest in history, which is attributed to food systems and the extensive land-use change. Moreover, food production also has a negative impact on the atmosphere as well as terrestrial and aquatic ecosystems, with severe implications for human health as well as wild species [5,6,7]. However, more than half of carbon emissions are captured by terrestrial and marine ecosystems; thus, their protection is vital in battling CC [8]. Moreover, the disruption to biodiversity directly affects human survival and is strongly related to prosperity, while the loss of biodiversity decreases the ability of ecosystems to absorb GHG [9,10,11].

GHG emissions related to fish production, either farmed or caught, is 4% of total anthropogenic emissions [12], while the increase in population has increased the demand for fish products. Based on different scenarios, the projected increase of fish demand by 2030 will be covered either by a sudden growth in aquaculture or an increase in fisheries capture productivity [13]. Nevertheless, industrial scale fishing constitutes a big threat for marine biodiversity and largely affects marine ecosystems due to overfishing, habitat destruction, deserted fish gear, and bycatch [14,15,16,17,18,19,20]. Furthermore, active wild-caught seafood is an energy-intensive method while passive wild-caught seafood relies on more sustainable methods as less bycatch is produced, and less fuel is utilized [21,22]. Although fish production is highly dependent on fish gear, it directly affects the marine ecosystem as it limits resources and occasionally disturbs the seabed. Indirect pressure is posed by the aquaculture of carnivorous species [23,24]. To an extent, waste production by aquaculture activities increases as well. The main sources of waste in aquaculture are (a) feed, (b) chemicals, and (c) pathogens [25]. Aside from providing seafood, ocean capture produces significant carbon dioxide emissions and stores heat. As such, the carbon sink capacity has been exceeded, and the ocean’s chemistry has altered, resulting in a 30% increase in acidification. The consequences of climate change to the oceans already observed are sea-level rise, water temperature warming, and deterioration in marine biodiversity [26].

Life cycle assessment (LCA) is a well-established method for capturing the consequences of the fishing sector on CC, as well as the environmental impact of products in general [27]. To this end, LCA publications for the fishing sector have significantly increased in the last decade [28]. Early LCAs on farmed fish pointed out that feed production exhibits the largest environmental burden in their life cycle [29,30,31,32] as well as the energy used to sustain water quality [31,33]. More recent LCA studies on fish farming highlighted feed as the most impactful process of aquaculture [34,35,36,37]. LCAs on the fish life cycle, including production processing and consumption, displayed production as the most impactful stage [38,39,40], while a strong dependency between impact calculations and species farmed was displayed [37]. In fishery capture, LCA is still evolving to address crucial environmental sustainability factors more efficiently. Main factors that are challenging to depict are, for example, plastic (or any synthetic substance) pollution, or CC effect on fisheries. Moreover, deficit inventories of fishing hinge on the evolution of LCA when applied in the fishing sector [28]. In this direction, quite significant publications led to the formation of several Ecoinvent datasets [41,42,43]. Fish stocks are perpetual, and their management requires preassessment of their capacity to regenerate. Methodological issues regarding LCA implementation for wild fish caught is fish stock-management-related and research progressed in this direction [44].

The Greek fish industry does important work by providing both high-quality and large quantities of fresh seafood. This is because Greece has an extensive coastline, thus, fishing constitutes an important socio-economy activity, represented by 16,000 fishing boats in the Greek fleet, and 0.2 million tons of fish production in 2018. Greece is among the five EU member states that produce three-quarters of the total aquaculture production, both in quantity and value [45,46]. Based on the socio-economic importance of small scale and recreational fishing, it is important for fishing activity to be implemented under regulations to sustain fish stocks in Greek seas [47], also supporting its potentials for sustainable development [48]. Seabass and seabream are quite important fish species for the Mediterranean Sea, where 97% of world production comes from [49]. Production of seabass and seabream in Greek fish farms was environmentally assessed from “cradle to gate” using LCA. More specifically based on primary data from producers, the feed production process exhibited the highest impact while the importance of feed conversion rate is also highlighted [50,51,52]. A “gate to gate” approach for seabass and meagre production focused on packaging potential for GHG neutrality [53].

Avgotaracho Mesolongiou, a high-quality product, is the Greek protected designation of origin bottarga from Missolonghi–Etoliko. The traditional fishing technique was registered in the intangible cultural heritage of Greece as traditional craftmanship practiced by local cooperatives [54]. The production of Avgotaracho Mesolongiou requires only locally sourced materials and natural means [55]. These attribute unique characteristics as depicted from isotopic- and DNA-based analyses and distinguish it from other bottarga [56,57,58] depicted in the high-resolution melting (HRM) technique [59]. Existing LCAs focus on extensive and/or intensive aquaculture techniques and fishery capture of wild fish. To the best of our knowledge, bottarga production has not been environmentally assessed yet within the existing literature.

This study aims to apply the LCA methodology to depict the environmental impact of authenticated Greek PDO “Avgotaracho Mesolongiou” and identify the hotspots of the overall production process. Avgotaracho Mesolongiou is produced from the roe of Mugil cephalus that are caught in permanent fish-catching facilities that are constructed in the lagoon complex of Missolonghi–Etoliko and are among the fish species harvested. The extracted fish are wild and are spawning in the lagoon, thus, they are fed naturally. The waste produced from the infrastructure of fish-catching facilities is further analyzed for alternative end-of-life management. The alternative scenario for waste management is compared with the baseline scenario using the LCIA. The calculations were conducted in Simapro (version 9.5.0.0), utilizing the recipe midpoint (H), and the inventory was compiled using the datasets of the Ecoinvent database [60,61,62].

2. Materials and Methods

2.1. Background Information: The Case Study of Klisova Lagoon Fish-Catching Facilities

“Avgotaracho Mesolongiou” is the Greek PDO bottarga, produced within the region of Missolonghi–Etoliko using raw material from the region and by all-natural means. Specifically, “Avgotaracho Mesolongiou” comes from the ovaries of Mugil cephalus (flathead grey mullet) caught in the lagoons’ complex of Missolonghi–Etoliko. Further processing takes place in the Anagenisi cooperative lab, the uniquely certified lab for “Avgotaracho Mesolongiou” production, involving roe extraction, curing with natural salt from Missolonghi, drying in ambient conditions, and waxing with natural wax from the area [55]. In January 1994, “Avgotaracho Mesolongiou” was officially declared a PDO product by the Greek government. The qualifications for labeling “Avgotaracho Mesolongiou” were briefly described in the official government gazette [63], while a more elaborate description of the peculiarities of this product’s characteristics was presented in the technical report of the recognition application [64] submitted from the local interested parties. Recent scientific interest for the “Avgotaracho Mesolongiou” was drawn to develop a production prediction model and describe details of its processing stages [65,66].

The supply chain is distinguished in the stages of fish extraction and the roe processing into Avgotaracho Mesolongiou. Missolonghi–Etoliko lagoon complex is divided into nine public fish-catching facilities leased and operated by local fishing cooperatives. The fish harvest takes place in the fish-capturing facilities, which are constructed to trap fish based on their movement within the lagoon. Klisova lagoon, one of the nine lagoons of the complex, which is leased by Anagenisi cooperative, has two types of fish-catching facilities, modern and traditional. With respect to the operation process, both constructions are taking advantage of the tidal cycles of lagoons and the tendency of fish to move against the stream. Furthermore, maintenance activities take place every year to repair damaged parts of fish-catching facilities. Nowadays, two traditional and two modern fish-catching facilities are operating in Klisova lagoon. Modern fish catching facilities are made of concrete and steel while traditional facilities are made of wood, plastic, and steel while cooperatives use their fleet of traditional boats (“gaites”) to approach facilities [67,68,69].

Roe processing takes place in the processing lab of the “Anagenisi” cooperative. The production of “Avgotaracho Mesolongiou” involves the transfer of fish to the facilities in plastic deckles with ice; the extraction, washing, and curing of roes; and the washing, drying, and waxing of cured roes and packaging. All processing techniques are traditional and require natural products (wax, salt) produced within the region of Missolonghi. Fresh ovaries weigh on average 300 to 700 g, reported as 20% of the total fish weight, and during drying they face 33% weight reduction while wax should increase their weight by 20% [66], while the mean weight of Avgotaracho Mesolongiou was calculated as 165.2 ± 39.4 g [62].

2.2. Goal and Scope

The purpose of this study is to conduct a whole life cycle environmental impact assessment of the “Avgotaracho Mesolongiou” production. The expected outcome illustrates the hotspots of the overall process to be used as a baseline for the development of an alternative scenario to be compared. PDO labeled “Avgotaracho Mesolongiou” comes from fish caught in Missolonghi–Etoliko lagoon complex fish-catching facilities and processed in the uniquely certified laboratory of the “Anagenisi” Cooperative. The functional unit is the 135 g of “Avgotaracho Mesolongiou” positioned in a delicatessen shop in Athens, Greece using average production quantities.

The examined system boundaries include the fish capturing in Klisova lagoon facilities, while the processing stage involves roe extraction, curing, and waxing in the certified lab of the “Anagenisi” cooperative. Furthermore, the transportation to Athens and positioning in a local delicatessen shop was considered along with the generated waste streams coming from the maintenance of fish-catching facilities and roe processing. The system boundaries and the corresponding supply chain of “Avgotaracho Mesolongiou” are presented in Figure 1.

2.3. Inventory Analysis

Life cycle inventory (LCI) of “Avgotaracho Mesolongiou” includes background and foreground materials and processes used to construct, maintain, and operate fish-catching facilities, process Mugil cephalus roes, and package and position the product in retail shops. The LCI was filled with primary data, findings from the literature, and assumptions. Accordingly, the methodological steps include, (a) research of the literature to depict the supply chain, (b) a questionnaire formulation to be addressed to the selected producer, (c) data retrieval through the questionnaire, (d) oral communication with producers for clarifications, and (e) research of the literature for missing data collection and assumptions’ formulation to fill in the gaps of the LCI.

The literature findings were used to formulate a questionnaire for primary data acquisition (see Appendix A). The formulated questionnaire was sent to “Anagenisi” cooperative, which operates the only certified lab for Avgotaracho Mesolongiou production, to retrieve data. “Anagenisi” cooperative filled in the questionnaire while verbal communication followed to clarify certain answers. To help depict background processes, the LCI was modelled in SimaPro software using both Ecoinvent 3.9 and Agrifootprint datasets. The inputs of Avgotaracho Mesolongiou supply chain are presented per stage in the detailed description of LCI included in the following sections.

2.3.1. Extraction of Mugil Cephalus

Avgotaracho Mesolongiou comes from the ovaries of Mugil cephalus extracted from the Klisova lagoon. Extraction occurs at fish-catching facilities, both modern and traditional, which operate based on the same principle, trapping fish by taking advantage of their tendency to move against tidal stream. During the stage of fish catching, several other species of fish are extracted, accounting for 67 tons in 2021 while the corresponding catch suitable for Avgotaracho Mesolongiou production weighed 500 kg. Modern fish-catching facilities are concrete structures resembling bridges with vertical metallic traps, while traditional fish-catching facilities are trapezium-shaped constructions placed in the lagoon with plastic fences supported by wooden poles with steel traps in the corners (see Figure 1). Modern fish-catching facilities are placed in canals that connect the open sea and the lagoon and control the intro and outro of the lagoon. Traditional fish-catching facilities are placed in the lagoon and control the passage to the canals by forcing fish to move through the facility.

The technical characteristics of traditional facilities are as follows: the holes of the plastic fence that surrounds the facility must be 13 mm, wooden poles made of chestnut wood, and placed between 30 to 40 cm distance and their height to be around 2.5 m (1 m under the bed of the sea, 0.5 m in the sea, and 1 m above the sea level). The nonparallel sides of the facility are almost 60 m long. While the smallest side of the trapezoid is 8 m long and is placed towards the open sea, its parallel side is V-shaped and 20 m long with an opening in the middle to trap fish inside the facility. The facility possesses five traps that are reversed u-shaped, 2 m wide and 1.5 m high with a steel framework. In Figure 1, the red marked positions in the perimeter of the facility are the traps and the opening is placed between the upper right and left corner. On the other side, regarding modern facilities, there was lack of available technical characteristics, and the amount of concrete and steel used was based on the dimensions as spotted in Figure 1 and the reported layout [69]. As such, the length of the facilities is 27 m, and the width is 3.7 m while the height is assumed to be 3 m. The calculations of concrete amount are more thoroughly presented in the Assumptions section.

Traditional fish-catching facilities are vulnerable to sea streams and erosion due to their consistency of materials and the placement in the lagoon. As such, wooden poles are subject to erosion and often require substitution while the plastic fence can be carried away by sea streams and is also frequently substituted. Modern facilities are more robust and resilient to sea water erosion and streams. The steel constructions used for trapping fish are made of Peraluman material, which is resistant to erosion. Maintenance activities of the fish-catching facilities are reported as quite significant but not predictable. As such, the replacement of the existing materials is subject to estimations. The estimated amount of materials used in fish extraction stage, their estimated lifetime, and yearly replacement are presented in

Table 1. Bill of materials for fish extraction stages.

Fish Catching Facilities	Material	Amount	Lifetime, y	Replaced Amount	EoL
					Baseline	Improved
Modern	Concrete, m3	31.91	30	1.06
	Steel, kg	3312.2	30	110.41	Sanitary landfill	Recycling
Traditional	Plastic, kg	72.7	5	14.54	Sanitary landfill	Recycling
	Wood, m3	41.8	20	2.09	Open burning	Municipal incineration
	Steel, kg	1207.9	30	40.26	Sanitary landfill	Recycling
Fleet (10 boats)	Wood, m3	8.9	50	0.18
	Cast iron, kg	189.8	20	9.49
	Steel, kg	70.2	20	3.51

.

The lifetime of chestnut wood used in sea water structures was found to be 15–25 years without considering marine borer attack, while steel resistance to corrosion depends on the conditions [70]. Concrete and steel constructions lifetime are estimated at 30 years due to the aggressive marine environment [71]. The plastic fence lifetime is assumed to be 5 years due to the damage that occurs from tidal streams. The waste amounts are presented in Table 1 for each material. According to Construction and Demolition Waste management report in Greece, CDW treatment facilities do not accept metals and plastics while wood wastes are mainly disposed [72]. The baseline end-of -life treatment scenario for each material is presented in Table 1 and is based on official reporting for CDW treatment in Greece, as well as considering the remote location of facilities. Furthermore, an improved waste treatment scenario is also presented in Table 1.

2.3.2. Avgotaracho Mesolongiou Production Stage

Avgotaracho Mesolongiou production takes place between August and October when fishing of Mugil cephalus is permitted. The extracted fish are placed in plastic deckles with ice and transferred to the processing facilities. In the processing facilities, which are solely used for Avgotaracho Mesolongiou production, the fish ovaries are carefully extracted and washed, followed by curing in natural salt, drying in ambient temperature, and being waxed in natural wax. All the materials used in the processing are extracted or/and produced in the region of Missolonghi. The processing facility is a building within the area of the lagoon, close to the fish-catching facilities. The bill of materials for roe processing is presented in

Table 2. Bill of materials for roe processing stage.

Avgotaracho Production	Material	Amount
Processing plant (t/y)		1 (1 t/y)
Roe processing	Water, L	2.5
	Salt, g	300
Packaging	Wax, g	20
	Plastic, g	10

.

2.3.3. Transport and Retail

Avgotaracho Mesolongiou is produced in very limited quantities, averaging 50 kg per year. As such, most of these quantities are channeled to delicatessen shops mainly located in Athens. The distance travelled from Missolonghi to Athens is almost 350 km. Furthermore, Avgotaracho Mesolongiou is a shelf-stable product with a long lifetime.

Table 3. Bill of materials for transport and retail stage.

Transport and Retail	Material	Amount
Transport	Mini van, km	241
Positioning	Heat, MJ	1.8 × 10−2
	Electricity	4.2 × 10−3

displays the bill of materials for transport and retail.

2.3.4. Allocation Factor

Avgotaracho Mesolongiou production is based on wild fish harvesting. As such, the produced quantities vary every year, while fish extraction occurs in permanent fish catching facilities, the lifetime of which expands according to the duration of materials in time as presented in Table 1. Accordingly, the inventory of the roe processing stage is also expanding to a lifetime beyond the production period due to the processing facilities, even though most materials are consumables. To allocate the inventory inputs according to the functional unit, inputs should be adjusted to the longevity of fish catching and processing facilities, as well as all products (functions) provided by the same examined system.

Fish Extraction Stage

The primary objective of fish-catching facilities in Missolonghi–Etoliko lagoon complex is fish production. Flathead grey mullet, which contains raw ovaries processed to Avgotaracho Mesolongiou, is also caught within these facilities, among other species. Besides the cultural aspect, Avgotaracho Mesolongiou possesses a high economic significance, since is priced at EUR 230 per kg. As such, the allocation factor of fish-catching facilities is calculated in respect to the economic value of Avgotaracho Mesolongiou.

Roe Processing Stage

The materials used in the production of Avgotaracho Mesolongiou are consumables, water, ice, salt, wax, and plastic, and are already allocated based on the reported FU. The equipment used in roe processing, deckles, knives, and wax melting devices, are considered negligible due to their long lifetime. The allocation factor for roe processing facilities based on 50 kg average production per year is 2.7 × 10⁻³.

2.3.5. Allocated Input

The allocated input used to model the production of 135 g of Avgotaracho Mesolongiou integrates the lifetime of materials into the allocation factor of

Table 4. Calculation of weighting and allocation factor of Avgotaracho Mesolongiou.

	Average Production (Tons)	Average Pricing (EUR/Ton)	Weighting Factor	Allocation Factor (FU)
Raw fish (incl. Mugil cephalus)	66.9	15 × 103	0.98
Avgotaracho Mesolongiou	0.1	230 × 103	0.02	2.7 × 10−3

and Section Roe Processing Stage, and is presented in

Table 5. Life cycle inventory for the production and positioning of 135 g of Avgotaracho to a delicatessen in Athens.

Component	Materials/Processes	Amount
Traditional fish-catching facilities	Polyethylene, kg	3.93 × 10−3
	Chestnut wood, m3	5.65 × 10−4
	Aluminum alloy, kg	1.09 × 10−2
Modern fish-catching facilities	Concrete, kg	6.89 × 10−1
	Aluminum alloy, kg	2.98 × 10−2
Boats (gaita)	Pine wood, m3	4.82 × 10−5
	Cast iron, kg	2.56 × 10−3
	Steel, kg	9.84 × 10−4
Waste management	Open burning wood, kg	6.1 × 10−4
	Sanitary landfill metals, kg	4.2 × 10−3
	Sanitary landfill plastic, kg	3.93 × 10−3
Processing facility	Building, p	2.0 × 10−6
Washing water	Tap water, m3	1 × 10−3
Ice for fish transfer	Electricity, kWh	6 × 10−4
	Water, kg	0.55
Curing	Salt, kg	0.3
Waste management	Untreated wastewater, kg	1.55
	Untreated salt, kg	3 × 10−1
Packaging	Wax, kg	0.02 kg
	Polyethylene, kg	1.0 × 10−2 kg
	Paper, kg	5.0 × 10−3 kg
Transportation	Truck, kgkm	32.4
Retail	Heat, MJ	1.8 × 10−2

.

2.3.6. Assumptions

LCI compiled information from the three stages of Avgotaracho Mesolongiou supply chain, fish extraction, roe processing, and retail, and contained data retrieved from producers via questionnaire, research of the literature, and assumptions. The assumptions used per stage are presented in this section and justified.

Fish Extraction

The input for fish extraction stage was merely based on assumptions supported by robust findings in the literature. The assumptions per input/material are presented in this section.

• Concrete: Figure 1 shows an overview of modern fish-catching facilities. The length and width as depicted in Figure 1 are 27.1 m and 3.5 m, respectively. The height of modern construction was assumed to be 3 m;
• Plastic: The density of plastic fence was calculated using a commercial product described as a 2-by-25-foot fence weighing 10.4 ounces. Following the conversion, the density is 0.065 kg/m² (based on commercial product);
• Steel: The radius of the metallic frames used in the traps of the “Traditional” fish-catching facilities was assumed to be 6 cm. There is no literature-based evidence to support this assumption;
• Wood: The wooden poles are placed every 30–40 cm, based on the literature [27]. In this study, an average placement of 35 cm was assumed. Moreover, the asked quantity for wood is volumetric, so a radius of 10 cm was assumed to calculate the volume of wood used;
• Fleet: In the traditional fish-catching facilities, the use of a boat is necessary to approach the traps and collect the captured fish. According to the literature, a wooden boat with a length of 6.5 m and a width of 1.5 m weighs 1000 kg [23], whereas the boats used in Klisova Lagoon have a length of 5 m and a width of 1.5 m [73]. Thus, based on the length-to-weight ratio of the “gaita,” its weight is assumed to be 700 kg. The type of material used, and the height of the boats was not considered within this assumption. Moreover, the volume of carpentry was calculated based on the assumption that eucalyptus wood is used for “gaita”, and the density is 560 kg/m³. Anagenisi cooperative consists of 10 people, thus, 10 boats and 10 engines were taken into consideration.

Roe Processing

The stage of roe processing was accurately described through primary data and concrete findings in the literature. However, to model the LCI of this stage, several assumptions were required, which are explained in this section.

• Ice: The amount of ice allocated for the transfer of the caught fish to the lab was assumed to be 5 kg. Based on the plastic deckle used, this corresponds to 2 cm in height. The amount of electricity used to make ice was calculated using data from the literature of snow production;
• Processing facility: The processing facility was modelled as a fish-curing plant, with an annual productivity of 2.700 t/y. The corresponding production capacity of Anagenisi Cooperative Lab was calculated to be 1 t/y. This calculation was based on the following assumptions: (a) based on the literature [24] 1 cured fish roe is dried on average for seven days, and (b) it is assumed that 64 fish roes can be dried simultaneously. Thus, for an average of 300 g per roe and 52 weeks per year, the resulting amount is 1 t/y;
• Wastewater: It was assumed that the water used for washing the extracted roe is provided by a typical water network based on European standards. However, no evidence is provided that the processing facilities are connected to the local water network. Moreover, the amount of washing water was assumed to be 1 kg;
• Packaging: Packaging materials, such as plastic film and paper, are assumed to have certain weights.

Transportation and Retail

The product was assumed to be positioned in a delicatessen shop in Athens and the distance is equivalent to travelling from Missolonghi to Athens without any specific destination.

3. Results

3.1. Avgotaracho Mesolongiou Hotspot Analysis

The inputs presented in Table 5 were used to calculate the baseline impact assessment, characterized and normalized factors, of Avgotaracho Mesolongiou with the help of Simapro software and ReCiPe midpoint (H) methodology for 18 impact categories. The normalized impact scores, displayed in Figure 2, based on the average global citizen emissions for one year, help depict the significance of the calculated impact within each category. As exhibited in Figure 3, human carcinogenic toxicity, freshwater, and marine ecotoxicity impact scores stand out among the 18 impact categories. More specifically, 50% of the total normalized score is attributed to human carcinogenic toxicity, 25% to freshwater ecotoxicity, and 18% to marine ecotoxicity, while freshwater eutrophication accounts for 2% of the total normalized scores.

Within these categories, the impact of seven processes exhibits the biggest influence. Metallic traps are clearly the most impactful process, assigned 71.4% of the total normalized impact score. More specifically, metallic traps contribute 60%, 88%, and 89% to human carcinogenic toxicity, freshwater, and marine ecotoxicity, respectively. Moreover, cast iron and steel used in boat engines account for 9.5% of the total impact score while concrete contributed another 5.6% in the total normalized impact. Consequently, the fish extraction stage is clearly the most impactful stage of Avgotaracho life cycle, which is further burdened by poor waste management. More specifically, largely due to wood open burning (4.9%), waste materials treatment of fish extraction stage account for 5.5% of the total normalized impact score.

At the processing stage packaging materials of Avgotaracho Mesolongiou, wax, plastic film, and paper account for 2% in total of normalized impact scores. While wastewater disposed in the lagoon accounts for 30% of freshwater eutrophication impact. Quite importantly, transport accounts for 4% of the total normalized impact score, possessing 3.5% of human carcinogenic toxicity impact, 3.2% of freshwater, and 14% of marine ecotoxicity. Overall, the life cycle of Avgotaracho Mesolongiou affects mainly human health due to the use of metallic traps and the ecotoxicity of aquatic ecosystems.

The characterization scores of processes are summed per stage and per impact category and presented in Figure 3. More specifically, in the fish extraction stage, the impact from plastic, concrete, metallic traps, wooden poles, boats, and the waste streams of plastic, wood, and aluminum were added. Accordingly, the roe processing stage includes washing water, packaging materials (wax, plastic film, paper), processing facility, and wastewater, while the transport and retail sum up the impact of retail electricity and heat as well as the transportation. As displayed in Figure 3, the impact is unequally allocated between the stages of Avgotaracho Mesolongiou life cycle. The fish extraction stage is the most impactful, contributing more than 78% of impact per stage on average. Especially in human carcinogenic toxicity, which was proven to be the most impactful category based on normalized scores, 92% of its impact is attributed to fish extraction stage as well as 95% to both freshwater and marine ecotoxicity. The roe processing stage contributes the most in marine eutrophication due to uncontrolled disposal of wastewater, as well as to water consumption due to the use of washing water and ice.

3.2. Comparison of Avgotaracho Mesolongiou Baseline Scenario to Improved Waste Treatment Methods

The hotspot analysis exhibits the impact on human carcinogenic toxicity, freshwater, and marine ecotoxicity with a significant contribution of waste stream’s treatment. As such, the baseline scenario for waste treatment is compared to controlled treatment options for their environmental impact as displayed in Figure 4. More specifically, plastic and aluminum disposal in sanitary landfills were replaced by recycling, waste wood open burning by municipal incineration, and wastewater disposal by wastewater treatment. As a result, the improved waste treatment scenario exhibits a 12% on average improvement in each impact category. Most significantly, human carcinogenic toxicity decreased by 8% while freshwater and marine ecotoxicity remained almost the same. More specifically, waste wood treatment impact on human carcinogenic toxicity decreased from 1 × 10⁻³ for open burning to 7.6 × 10⁻⁵ for municipal incineration. Moreover, wastewater impact on freshwater eutrophication decreased from 1 × 10⁻⁴ for uncontrolled disposal to 1 × 10⁻⁵ for the average wastewater treatment. Furthermore, waste plastic treatment impact decreased by 14% when recycled compared to sanitary landfill disposal, while metallic trap treatment imposes a slightly higher impact when recycled in relation to sanitary landfill. Most specifically, aluminum recycling imposed a burden in 6 out of 18 impact categories, on human carcinogenic toxicity, freshwater, and marine ecotoxicity, among others.

The impact contribution per life cycle stage is displayed in Figure 5 for improved waste treatment in the Avgotaracho Mesolongiou life cycle. Fish extraction stage impact was improved by more than 1% and accounts for 77% on average per impact category. Most significant improvement is spotted in water consumption, in which controlled wastewater treatment imposes a positive impact while municipal incineration of wood waste results in a tenfold improvement in overall normalized impact score. More specifically, wastewater impact decreased from 0.6% to 0.1% and waste wood impact from 6% to 0.6% of the overall normalized score.

The fish extraction stage’s potential to improve was larger since three major waste streams were attached to this stage, while roe processing produced only the wastewater stream, and transport and retail stage had no waste stream. The resulting on average improvement per impact category is almost 5%, from 81.8% for baseline scenario fish extraction, to 77.1% when improved waste treatment is implemented. Fish extraction impact decreased in 16 out of 18 impact categories while in human carcinogenic toxicity, a 52% decrease was observed for the fish extraction stage due to improving waste wood treatment. On the other hand, an improvement in the roe processing stage is observed in freshwater eutrophication and water consumption due to proper treatment of wastewater.

3.3. Sensitivity Analysis

In the section of sensitivity analysis, a further analysis is carried out in respect to specific inputs of the inventory that have been assumed during the inventory analysis and are likely to influence the outcome. In the Avgotaracho Mesolongiou life cycle, materials used in the fish extraction stage exhibit the largest influence. Moreover, research on the literature on aluminum and wood used in traditional facilities would justify certain variations that were simplified during the Section 2.3.6. As such, in the following sections, a sensitivity analysis is conducted in respect to metallic traps radius of traditional facilities as well as the placement of wooden poles on the fence of traditional facilities.

3.3.1. Radius of Metallic Traps

Aluminum quantities used in metallic traps in the traditional fish-catching facilities, which account for 26.7% of the total aluminum used in the fish extraction stage, were calculated based on assumptions made for their radius. The Avgotaracho Mesolongiou inventory assumed a 3 cm radius. As such, the system is tested for radii of 2 and 4 cm and the results are displayed in Figure 6. The largest variation is exhibited in freshwater and marine ecotoxicity as well as human carcinogenic toxicity impacts. More specifically, freshwater and marine ecotoxicity impact may decrease by 12% for a 2 cm radius while it could increase by 20% for a 4 cm radius, while human carcinogenic toxicity could potentially decrease by 8% for a 2 cm radius and increase 13% for a 4 cm radius. On the other hand, land use was only slightly influenced by the change in aluminum quantity; there is a 6% average improvement when using 2 cm radius metallic traps, while almost 10% is the increase in impact on average per category when using a 4 cm radius.

3.3.2. Wooden Pole Placement

The wooden poles are supporting the fence in traditional fish-catching facilities and are placed every 30–40 cm. To calculate the amount of wood used, a 35 cm placement was assumed. The influence of assuming 30 cm and 40 cm placement of wooden poles is examined and the results are displayed in Figure 7. As a result, land use has been majorly influenced; the potential decrease using a 40 cm placement is almost 10%, while a 30 cm placement imposed a 13% increase. The average improvement potential per category is 0.5% when using a 40 cm placement, while 0.6% is the potential to increase impact per category when using a 30 cm placement.

4. Discussion

Hotspot analysis of the Avgotaracho Mesolongiou life cycle exhibits a large impact on human carcinogenic toxicity, and freshwater and marine ecotoxicity. Human carcinogenic toxicity impact occurs mainly due to chromium (VI) emissions to water as well as airborne emissions of formaldehyde and polycyclic aromatic hydrocarbons (PAH), as displayed in

Table A2. Inventory of Avgotaracho Mesolongiou baseline scenario characterization emission factors for human carcinogenic toxicity.

Substance	Compartment	Unit	Total	Aluminum Alloy, AlMg3	Concrete	Cast Iron	Iron–Nickel–Chromium Alloy	Packaging Film	Transport	Waste Wood, Open Burning
Total of all compartments		kg 1,4-DCB	0.12	0.07	0.01	0.01	0.01	1.31 × 10−3	4.66 × 10−3	0.01
Chromium (VI)	Water	kg 1,4-DCB	0.1	0.07	0.01	0.01	4.26 × 10−3	1.21 × 10−3	4.21 × 10−3	x
Formaldehyde	Air	kg 1,4-DCB	0.01	9.1 × 10−6	5.01 × 10−5	2.25 × 10−7	6.33 × 10−7	6.55 × 10−6	2.94 × 10−4	0.01
PAH, polycyclic aromatic hydrocarbons	Air	kg 1,4-DCB	3 × 10−3	2 × 10−5	2.43 × 10−6	1.29 × 10−7	1.38 × 10−7	2.94 × 10−7	3.29 × 10−7	2.98 × 10−3

. More specifically, more than 50% of chromium (VI) emissions are attributed to aluminum production, while concrete, cast iron, steel, and waste wood open burning are also significant sources. Actually, Cr(VI) is used as a minor additive to aluminum alloys and is very common in ferroalloys and wood furniture [74,75]. Moreover, the emitted formaldehyde, the product of incomplete wood burning, [76] and polycyclic aromatic hydrocarbons (PAHs) [77,78] are both sourced from waste wood open burning. As a matter of fact, both compounds, formaldehyde and PAH, were reported as carcinogens [79,80]. The second most impactful category is freshwater ecotoxicity, mainly attributed to copper ion, zinc (II), vanadium, chromium (VI), and nickel (II) being emitted into water, as exhibited in

Table A3. Inventory of Avgotaracho Mesolongiou baseline scenario characterization emission factors for marine ecotoxicity.

Substance	Compartment	Unit	Total	Aluminum Alloy AlMg3	Concrete	Iron–Nickel–Chromium Alloy	Packaging Film	Transport	Waste Polyethylene
Total of all compartments		kg 1,4-DCB	0.18	0.16	4.94 × 10−3	4.42 × 10−3	1.09 × 10−3	0.01	1.18 × 10−3
Copper, ion	Water	kg 1,4-DCB	0.15	0.14	2.16 × 10−3	2.03 × 10−3	4.8 × 10−4	2.51 × 10−3	3.01 × 10−5
Zinc (II)	Water	kg 1,4-DCB	0.02	0.01	1.82 × 10−3	1.16 × 10−3	4.19 × 10−4	3.22 × 10−3	2.28 × 10−4
Vanadium (V)	Water	kg 1,4-DCB	4.95 × 10−3	3.45 × 10−3	2.74 × 10−4	3.34 × 10−5	X	1.47 × 10−4	8.92 × 10−4
Chromium (VI)	Water	kg 1,4-DCB	1.81 × 10−3	1.22 × 10−3	1.5 × 10−4	7.45 × 10−5	2.12 × 10−5	7.36 × 10−5	5.91 × 10−7
Nickel (II)	Water	kg 1,4-DCB	1.45 × 10−3	5.2 × 10−4	1.22 × 10−4	6 × 10−4	4.56 × 10−5	6.95 × 10−5	3.16 × 10−7

. Copper ion emissions account for more than 80% of freshwater ecotoxicity sourced from aluminum production. Similarly, marine ecotoxicity is attributed to the same emitting factors and copper ion accounts for more than 90% of marine ecotoxicity. Furthermore, freshwater eutrophication is the fourth most important impact category due to the levels of phosphate, COD, and BOD being emitted. More specifically, the uncontrolled disposal of wastewater to the lagoon is responsible for all the localized effect of freshwater eutrophication. Globally, aluminum production is responsible for phosphate, COD, and BOD emissions in water, as presented in

Table A5. Inventory of Avgotaracho Mesolongiou baseline scenario characterization emission factors for freshwater eutrophication.

Substance	Compartment	Unit	Total	Aluminum Alloy, AlMg3	Concrete	Wastewater Disposed
Total of all compartments		kg P eq	2.76 × 10−4	1.14 × 10−4	2.18 × 10−5	7.91 × 10−5
Phosphate	Water	kg P eq	1.65 × 10−4	1.08 × 10−4	1.65 × 10−5	X
Phosphate, GR	Water	kg P eq	5.89 × 10−5	X	X	5.89 × 10−5
Chemical oxygen demand (COD)	Water	kg P eq	1.91 × 10−5	4.33 × 10−6	4.03 × 10−6	X
Chemical oxygen demand (COD), GR	Water	kg P eq	1.37 × 10−5	X	X	1.37 × 10−5
Biological oxygen demand (BOD5), GR	Water	kg P eq	6.48 × 10−6	X	X	6.48 × 10−6
Biological oxygen demand (BOD5)	Water	kg P eq	5.81 × 10−6	1.44 × 10−6	1.03 × 10−6	x
Phosphorus	Water	kg P eq	4.62 × 10−6	1.29 × 10−7	1.59 × 10−7	x
Phosphorus	Soil	kg P eq	2.83 × 10−6	1.87 × 10−8	6.39 × 10−9	x

. Phosphate emissions to water was mainly attributed to aluminum production and is related to the refining process [81].

Life cycle assessment of aquaculture techniques demonstrate the high impact of feed production and energy use while infrastructure was the least impactful and influenced mostly marine toxicity and energy demand. The most influenced impact categories of aquaculture LCAs were land use, water consumption, and eutrophication potential, mainly attributed to feed production and energy use [37]. However, the depicted hotspots of aquaculture are not considered relevant to Avgotaracho Mesolongiou production, due to feeding absence, while no energy is required to sustain water quality in the facilities.

When implementing alternative controlled waste treatment processes, the life cycle impact calculations of Avgotaracho Mesolongiou production decrease, as displayed in Figure 4. More specifically, wood waste municipal incineration instead of open burning results in a significant improvement in human carcinogenic toxicity impact. Formaldehyde and PAH emissions are not major contributors to human carcinogenic toxicity, as presented in

Table A6. Inventory of Avgotaracho Mesolongiou improved waste treatment scenario characterization emission factors for human carcinogenic toxicity.

Substance	Compartment	Unit	Total	Aluminum Alloy, AlMg3	Concrete	Cast Iron	Iron–Nickel–Chromium Alloy	Packaging Film	Transport	Waste Wood, Municipal Incineration
All compartments		kg 1,4-DCB	0.108	7.1 × 10−2	8.8 × 10−3	1.24 × 10−2	5.6 × 10−3	1.3 × 10−3	4.7 × 10−3	7.83 × 10−4
Chromium (VI)	Water	kg 1,4-DCB	0.1	6.9 × 10−2	8.5 × 10−3	1.24 × 10−2	4.26 × 10−3	1.21 × 10−3	4.21 × 10−3	7.29 × 10−4
Chromium (VI)	Air	kg 1,4-DCB	1.03 × 10−3	1.64 × 10−4	1.67 × 10−5	5.25 × 10−7	7.85 × 10−4	1.92 × 10−5	1.03 × 10−5	3.94 × 10−6
Arsenic, ion	Water	kg 1,4-DCB	8.29 × 10−4	5.81 × 10−4	5.15 × 10−5	4.07 × 10−6	6.78 × 10−5	2.21 × 10−5	3.35 × 10−5	3.88 × 10−5
Nickel (II)	Water	kg 1,4-DCB	5.84 × 10−4	2.08 × 10−4	4.86 × 10−5	3.93 × 10−6	2.39 × 10−4	1.82 × 10−5	2.77 × 10−5	5.38 × 10−6

, and account for less than 0.1% of the emissions. The consequent decrease in formaldehyde and PAH corresponds to almost 100%, resulting in an overall 8% decrease in human carcinogenic impact. Furthermore, freshwater eutrophication was also largely improved. The shift between uncontrolled disposal of wastewater to a wastewater treatment process resulted in minimizing the effects on a local level, causing a 26% drop in freshwater eutrophication.

The Missolonghi–Etoliko lagoon complex is a large aquatic ecosystem that is systematically exploited by agricultural cooperatives, taking advantage of the spawning of several fish species. The fish-catching facilities used in the area are steady complex structures based on a traditional fish-catching technique developed in the area. Currently, both traditional and modern fish-catching facilities coexist and generate waste streams that are embodied accordingly to compare their environmental performance. The infrastructure used in Avgotaracho Mesolongiou is proven to be the more impactful component of its life cycle while modern infrastructure accounts for the largest impact due to higher quantities of aluminum. Further confirmation of aluminum influence on the system and the impact on modern facilities was achieved by conducting sensitivity analysis on the input of aluminum in traditional facilities. On the other hand, the variation in wood input mostly influenced land-use impact category.

Other considerations that arise from fishing activities are marine debris, fish stock management, and by-catches. More specifically, it is reported that 120 million tons of plastic are emitted into the oceans and provoke environmental damage. The omitted plastic is dangerous for the life of wild species and may be degraded and release other toxic substances as well as produce microplastics that enter the human food chain [28]. Traditional fish-catching facilities use plastic fences to limit the movement of fish. Fish cooperatives reported that due to tidal streams, parts of the plastic fence can be destroyed and need to be replaced. Regarding by-catches and fish stock management, modern facilities were established to improve these areas. More specifically, the opening between the bars in modern fish-catching facilities was reported to let fish that are not appropriate to pass. However, neither plastic pollution nor fish stock management issues are addressed in this study.

5. Conclusions

The Avgotaracho Mesolongiou impact is merely coming from the fish extraction stage, which accounts for 78% of the impact on average per impact category. More specifically, metallic traps used in the fish extraction stage account for 44% per impact category averagely and 70% of total normalized score. The generated waste of fish extraction stage is responsible for 9.5% on average per impact category, while waste wood open burning accounts for 9%, affecting mostly global warming, stratospheric ozone depletion, ozone and fine particulate matter formation, terrestrial acidification, and human carcinogenic toxicity. The processing stage of the Avgotaracho Mesolongiou life cycle is subjected to regulatory requirements. As such, roe processing is not flexible to variations. However, 29% and 44% of the impact of freshwater and marine eutrophication are attributed to the uncontrolled disposal of wastewater.

Although the life cycle of Avgotaracho Mesolongiou is not flexible and, thus, possesses a relatively steady environmental performance, several waste streams in the baseline scenario were not treated appropriately. However, when subjected to controlled treatment processes, they exhibited an improved environmental performance. More specifically, waste wood treatment impact decreased by 87% when subjected to municipal incineration compared to open burning. As a result, human carcinogenic toxicity impact improved by 8% while the average impact per category dropped from 9% to almost 2%. Furthermore, freshwater eutrophication significantly improved when wastewater treatment was used compared to being disposed into the lagoon. In particular, freshwater eutrophication decreased by 92% and marine eutrophication decreased by 14%. The results were robust in terms of which impact categories were mostly influenced. Furthermore, despite several inputs being assumed, the outcome is not subject to large variations, given that assumptions were made on solid ground.

Although a thorough investigation was conducted, further research is required on several aspects of marine activities. The generated waste should be further explored, for example whether their total quantities are gathered or are lost in the sea. This point will determine whether Avgotaracho Mesolongiou production contributes to the marine debris coming from other fishing activities. Furthermore, the sustainability of this technique should be further explored to determine fish stock management issues that may arise. Moreover, it would be valuable to compare traditional fish-catching and processing techniques with conventional fishing methods and modern bottarga processing to determine the methods that are the most sustainable.