Course:CONS200/2023/Sustainable Fishing in the Adriatic Sea

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Fishing boat in the Adriatic Sea

The Adriatic Sea has been a long-term source of food and economic profit for countries in the eastern Mediterranean, particularly Croatia and Italy. However, due to overfishing and unsustainable fishing practices, many species of economic value including sardines, sole, mantis shrimp, and others have been greatly threatened[1][2]. The combination of increased demand for fish, advancements in fishing technology, and lack of effective management and regulations can be thought of as the main causes. In recent years, there has been a growing movement towards sustainable fishing, aimed to ensure safe fishing practices, and healthy levels of fish populations[2]. Sustainable fishing is defined as fishing practices that ensure the long-term health and productivity of fish populations, while also minimizing the negative impacts on the environment[2].

Despite large declines in fish populations, the challenges facing sustainable fishing in the Adriatic Sea are significant. Apart from overfishing, the region faces issues such as illegal, unreported, and unregulated (IUU) fishing, pollution, climate change, and the impacts of coastal development[3]. These challenges require a multi-faceted approach to address, involving a combination of policy and management measures, community engagement, and technological innovations [4]. Discussions on sustainable fishing only commenced after Croatia joined the European Union in 2013, as it opened a political channel of discourse between Croatia and Italy, the main benefactors of the Adriatic Sea[3]. The accession of Croatia resulted in the expansion of the Common Fisheries Policy (CFP) into the eastern Mediterranean region[1]. However, this policy had a number of drawbacks, mainly that it was not specified for regional management[1]. Beginning in 2014, the CFP began undergoing reforms, the main goal of which was to “bring decisions closer to those mostly affected,” and experts of the region[3]. Positive changes have then been observed over time especially through restrictive fishing practices, causing an increase in abundance and biomass of fish resources [5]. However, this effectiveness is challenged by social issues arising from disputes with artisanal fishers[4]. Additionally, while policy is important in creating frameworks of sustainability, more direct actions including fishing methods, and catch limitations must be explored in their efficacy as well to create a more holistic understanding of sustainable fishing.

History of Fishing in the Adriatic Sea

Coastal communities have engaged in economic activities in the Adriatic Sea since ancient times, with evidence of human habitation in the Mediterranean dating back more than 100,000 years[2]. The sea, located between Italy and the Balkans, has been an important fishing ground for centuries, providing food and economic profit[2]. Although fishing activity has been growing with population since the seventh century, it began rapidly intensifying in the late nineteenth century[2].

Map of the Adriatic Sea

Despite the use of relatively small-scale fishing gear, scientists still questioned the effects of the new fishing practices and demands on fish species[2]. Increased industrial activities also made species more vulnerable due to pollution, river alterations, and damming[2]. Fishing capacity experienced a significant increase during the late nineteenth century, followed by the motorization of fishing vessels in the early twentieth century, and further expansion towards offshore and deeper waters after World War II[2]. The peak of official catches was recorded in the 1980s and 1990s[2]. Presently, 70% of stocks that are economically valuable and 44% of all exploited stocks are believed to be overfished and beyond safe limits, with the harmful effects of fishing on species and their surrounding ecosystems being broadly acknowledged[2].

Implementation of Sustainable Fishing

With increased concern about overfishing, sustainable fishing methods were implemented. The Common Fisheries Policy (CFP) was developed in 1982 by the European Union to ensure the responsible use of marine resources[3]. The CFP was originally a regional policy, focused on the North Sea, yet eventually expanded across the European Union[3]. However, with this expansion in operation, the lack of regionalization was acknowledged as a drawback of the initial iteration of the CFP, but the subsequent reforms failed to tackle this issue[3]. In response to continued calls for regionalization, the 2014 reform focused on shifting away from a centralized authority and towards delegating power to regional bodies[3]. This crucial change aims to transfer power closer to those with a deeper understanding and experience of specific fisheries and the environment[3]. Furthermore, data collection for stock assessment has been significantly improving, providing better reference points for past successes as well as further action[3]. However, management in the Adriatic Sea is experiencing delayed actions due to inefficient coordination between each managing body, and further cooperation within the CFP is required to meet management goals[3].

Methods of Sustainable Fishing

Through the use of micro-level decisions and implementation of management tools, the once bountiful Adriatic Sea can regain its fish crops[1]. The main issue with implementing sustainable fishing practices is balancing the environmental benefits with the socioeconomic losses. The main technique being applied to the Adriatic Sea is the introduction of Marine Protected Areas (MPA)[6]. However, other regions are changing gear characteristics, catch limits, and the number of issued licenses in an attempt to combat overfishing [3].The effects of MPAs vary greatly depending on species, intraspecific and interspecific interactions, and the size of the area encompassed by the MPA[6].

Torre Guaceto MPA

To understand how MPAs will impact socioeconomic benefits and biodiversity decline, Carbonara analyzed the consequences for a singular species. The Adriatic Sea is host to many economically important species, and fishing in the south Adriatic is based principally on the catch of striped red mullet Mullus surmuletus[6]. By comparing abundance and growth patterns of female M. surmuletus in Monopoli and Molfetta, unprotected regions, versus Torre Guaceto, an MPA, the conservation impacts can be understood[6]. Torre Guaceto had a significantly greater catch per unit effort (CPUE) than either unprotected region[6]. The higher density contradicted previous studies showing population density was correlated with smaller fish; this discrepancy is likely due to the secondary effects of the MPA also promoting the health of key prey items for the striped red mullet[6]. Additionally, the MPA had an average bimodal length of 21 and 27cm, while Molfetta and Monopoli fish lengths were much shorter, 15-16cm[6]. Past research reveals a direct positive correlation between fish body size, reproductive fitness and fecundity[6]. The increased biodiversity benefits coupled with socioeconomic profits suggest MPAs are a feasible way to balance both goals in the Adriatic Sea. Furthermore, greater fish fecundity and density could potentially increase fish populations at a faster rate, thereby reducing the overall drop in catch limitations to hopefully better mitigate socioeconomic losses. However, these results are limited to a singular fish species, and are limited in their extrapolation to other species due to variances in behaviour and physiology.

Implementation of Buffer Zones

Bottom otter trawling setup targeting spottail mantis shrimp Squilla mantis, and common sole Solea solea.

However, studies focused on the GSA17, the most productive area of the Mediterranean Sea, found in northern part of the Adriatic basin, have found that buffer zones can lead to reduced revenue for certain fishing methods[1]. The GSA17 region is one of the most intensively fished regions of the Mediterranean, and through the use of bottom otter trawlers and rapido trawlers, catches are often composed of immature individuals[1].

In response, various trawling bans from the Italian GSA17 coast was modelled using the DISPLACE model framework[1]. Neither buffer showed a significant improvement in stock status for common sole, striped red mullet, hake, or spottail mantis shrimp[1]. Furthermore, the redistribution of trawling efforts has unknown consequences on seafloor integrity, possibly reducing overall ecosystem health[1]. While the removal of trawlers may benefit sea netter activities, a 6nm buffer could reduce trawler revenue by 10-15%[1]. However, low ex-vessel market prices of predominant catch species is a significant reason for low profits, not just catch volume[5]. These economic losses cannot be addressed by conservation efforts, and can instead be rectified by forming a network between markets to improve the negotiating power of fisherman[5].

Instead of MPAs, certain regions have instead enforced switching to more sustainable fishing methods such as gillnetting[1]. Unlike trawling, which catches fish regardless of size, gillnetting uses vertically floating nets with specific hole sizes based on the targeted species[7]. Young individuals, who are too small, can simply pass through the net, while mature individuals will be intercepted and stuck by their gills[7]. These young individuals then have more time and opportunity to reach sexual maturity, and increase the overall fish crop when compared to traditional fishing methods in the Adriatic Sea.

While there are many approaches possible to improving sustainability of fishing in the Adriatic Sea, the most fundamental part for its success is that the decisions and approaches are made at a micro-level using the knowledge of local experts and fishermen.

Effectiveness of Sustainable Fishing

The effectiveness of sustainable fishing must be analyzed with regards to multiple facets, due to the diverse range of factors involved. For instance, while maximizing the conservation and restoration of biodiverse marine ecosystems in the Adriatic Sea may be the goal of some, this goal neglects to understand the socioeconomic impacts from the reduction or eradication of fishing, and marine travel.

Marine Spatial Planning in the Northern Adriatic

One method to understand how different sustainability initiatives have impacted ecosystem health is through Marine Spatial Planning (MSP)[8]. MSP uses extensive qualitative knowledge involving the habitats, communities, biology, and interactions of selected fish species to allocate and manage human activities while balancing ecosystem health[8]. By combining MSP methodology with decision support tools (DSTs), the severity and regionality of anthropogenic stressors can be investigated[8].

In the study located in the Northern Adriatic Sea (Chioggia, Venice, and Rovigo), the largest use conflicts were from maritime traffic and trawling activities, which were quantified through the cumulative effect analysis (CEA)[8]. Maritime traffic represented a large portion of the CEA scores due to its heterogeneity across the region, and was present in all of the targeted areas[8]. The widespread nature of maritime travel means that local management is not feasible, and must be considered on a larger scale. In contrast, the studied region had a liquefied natural gas (LNG) plant, which despite its small area (1%), had the greatest single-cell CEA score due to a combination of waste material and underwater noise[8].

Trawling accounted for 50% of the relevant CEA score, with bottom trawlers presenting the greatest impact[8]. The principal catch species of the Adriatic Sea rely heavily on soft-bottomed ecosystems for recruitment and reproduction, which are the habitats most threatened by anthropogenic activities[8]. The large fishing equipment also has negative behavioural and mortality impacts to larger marine life including sea turtles and bottlenose dolphins[8]. Alternatively, small-scale fishing presents nearly irrelevant impacts compared to other human activities[8]. Additionally, the target region small-scale fishing accounts for the greatest number of vessels, and highest employment rates[8]. Nevertheless, due to the increasing global demand for seafood products, small-scale fishing is not economically fiscal on a global scale[8].

Therefore, increasing and optimizing no-trawl zones around habitat hot-spots can greatly increase overall ecosystem health and catch potential, as seen in the Torre Guaceto MPA[6][8].

Cartography of Littoral Rocky-Shore Communities

The European Union uses the Water Framework Directive (WFD), a legal framework, to monitor the ecological quality of European waters[9]. The data used for monitoring employs biological indicators that are correlated to an ecological status to estimate current conditions[9]. However, most methods overemphasize the homogeneity of water bodies[9]. In contrast, cartography of littoral rocky-shore communities (CARLIT) assesses the entire length and type of the coast through non-destructive visual observation[9]. This visual observation allows CARLIT to assign dominant macroalgae communities to each region along the Croatian coast (Eastern Adriatic Sea)[9].

The different macroalgae identified were given designated sensitivity levels on a scale from one to twenty, the greatest value given to fully developed Crystoseria forests, while the lowest were in highly polluted areas consisting mostly of green algae and cyanobacteria[9]. Additionally, the framework categorized abundance using a qualitative three-class system: continuous belt, abundant patches, and scattered patches[9]. The zones of interest were compared to reference values collected from sites with limited human impact[9].

  • Low population density
  • Small harbours (<100 boats)
  • No industries
  • No fish farms
  • No beach restoration

These sites were then compared with data from the Mediterranean Geographical Intercalibration Group, and were found to be consistent[9]. The results of the study found that degradation was highly concentrated around urban and industrial centres[9]. However, CARLIT outcomes are mainly impacted by eutrophication and general water quality degradation, and therefore is a better resource for understanding how population dynamics affect the Adriatic Sea rather than fishing activities[9]. Nevertheless, an interesting observation from the study was that 23% of the observed coast was heavily degraded due to the overgrazing of sea urchins[9]. Therefore, indirect conclusions on the impact of fishing activities may be drawn, as this sea urchin overgrazing is commonly associated with the overfishing of sea urchin predators[9].

Biodiversity Protection and MPAs

Pursuant to the Convention on Biological Diversity, Aichi Target 11 representing one of the key commitments in the European seas management, states that 10% of coastal and marine areas, especially the areas of particular importance for biodiversity, to be conserved by 2020[10]. The Mediterranean Sea has a coverage of 11.7%, with the Adriatic Sea having only 5.8% of the area covered by MPAs, while the Greater North Sea reached 27.1% by 2016, the highest proportion of any European regional sea[10]. Less than 1% of MPAs in Europe are marine reserves[10]. Out of the 1,231 MPAs in the Mediterranean in 2016, solely 76 MPAs include fully protected areas, whereby 50% of those cover the area that is less than 1 km2, meaning that only 0.04% is covered by fully protected MPAs[10].

Integrated classification of biodiversity condition in the Mediterranean Sea

Fully protected European MPAs (e.g. no‐take reserves) have been documented to deliver significant improvements in densities of species, species richness, body size, and biomass[10]. Further actions should also include the removal of the key pressures from the sites to allow recovery of species and habitats that they contain; and to ensure that the MPAs can act as a sanctuary zone for biodiversity from which the broader marine ecosystem can benefit as progression is made towards good environmental status (GES)[10]. It has been demonstrated that European MPA networks are more affected than non‐protected areas by commercial fisheries[10]. This questions the true benefit of the EU MPA network for marine biodiversity and shows that management efforts need to be strengthened, to prove they do benefit biodiversity in comparison with the outer network[10].

The network of MPAs is unfortunately not representative with regard to diversity of European seas, providing generally little protection[10]. The Birds and Habitats Directives (BHD) annexes that were agreed years ago neither incorporate recent scientific knowledge nor do they cover marine habitats sufficiently[10]. In 2015, the European Environment Agency (EEA) reported that significant aspects of marine ecosystem are excluded from formal protection schemes[10]. Reviewing BHDs annexes would therefore facilitate the protection under CFP rules[10]. MedReg does prohibit the catch of species listed in the Habitats Directive, but catching threatened species not listed in the Annex thereof remains legal[10].

Future Improvements

In relation to how artisanal fisheries along the Northern Adriatic Sea coast exhibit similar features (such as polyvalence and a large number of exploited species) to those in other European areas, several considerations are particularly important for future management improvements[11]. The high potential vulnerability to thermal changes must be taken into account due to species dependence and catch composition with regards to thermal affinity groups[11]. As fisheries with temperate and cold species contribute to all catches, they are exposed to negative effects from expected changes in nekton assemblages[12][13]. Moreover, although artisanal fisheries have shown to be a sustainable practice, Fabio recognizes the potential of how this can lead towards unsustainability in the future through small modifications in fishing fleet structure and environmental conditions[11]. If current levels of artisanal fishing remain parallel with present hydraulic dredging levels and persist as the sole fishing activities, future management strategies will also be required[11]. These strategies should be geared towards achieving the two goals of reducing conflicts between competing fishing fleet industries (since they usually share similar preferred fishing zones), and avoiding uncontrolled increases in fishing, which may outweigh the positive effects of the trawling ban if unchecked[11].

Future Studies on Effects of MPAs

Further effects of MPAs could also be evaluated in several different ways. To do this, Carbonara developed hypotheses that are testable for future research and can be carried out on other model species and in other geographic areas[6]. These hypotheses include:

  1. If further studies confirm that individual fish growth responds to fishing restrictions within MPAs, then this variable could be used to test the effects of fishing restrictions within MPAs[6].
  2. In addition to density and biomass, if fishing restrictions positively influence fish growth and reproducers’ size, then MPAs could once again demonstrate as crucial tools for preserving and boosting reproduction of local populations of commercially (and often ecologically) relevant species[6].
  3. If individual growth increases alongside increases in population density and biomass within MPAs, this suggests that marine ecosystems with effective fishing restrictions work differently by being significantly more productive than severely fishing-impacted ecosystems[6].

Considerations for Future Management Developments

In terms of the hake and common sole stocks, many stakeholders (fishers, policymakers, and scientists) have noted the sizeable benefits that can be gained by collecting more data on the stocks under study’s ability to disperse[1]. Future management frameworks should consider how fish population dynamics may experience spatial and temporal changes, and how fisheries can impact benthic habitats and communities[1]. The development of these models should facilitate decision-making by demonstrating the economic benefits of sustainable harvesting and stock replenishment, in which the economic and ecological effects of fishermen’s decisions and the fishery management are combined before implementation[1]. This is particularly relevant when gauging the spatial occupation of smaller and larger marine areas by numerous marine sectors, including offshore gas platforms, large marine constructions (like breakwaters), mussel farms, and commercial shipping with respect to their ecological and economic impacts (e.g. harvesting restrictions or resource protection) on fisheries, fishing communities, stocks, and other ecosystem components such as fishery impacts on benthic habitats[1]. There is also an expectation for practitioners to care at minimizing the marginal effect of displaying one unit of effort on seafloor integrity while maintaining the landings as far as possible[1].


The Adriatic Sea is a crucial habitat for the local inhabitants and hosts several commercially significant species due to its proximity to numerous nations. Sustainable fishing practices are necessary to ensure the continued health and productivity of the sea. However, overfishing, illegal fishing, and climate change has posed significant challenges to the sustainability of the Adriatic's fish population and the broader marine ecosystem over the years. With rising concern, the Common Fisheries Policy (CFP) was developed by the European Union in 1982 to promote responsible use of marine resources. However, despite subsequent reforms aimed at regionalization, the lack of coordination between managing bodies remains an issue, highlighting the need for greater cooperation within the CFP to meet sustainable fishing goals.

In terms of implemented sustainable fishing methods, the use of Marine Protected Areas (MPAs) has been successful for selected species in increasing biodiversity and socioeconomic profits, as demonstrated by the Torre Guaceto MPA. However, buffer zones have been demonstrated to decrease revenue for historic large-scale fishing methods, and alternatives like gillnetting are being enforced in some regions. Sustainable fishing also requires the involvement of local experts and fishermen decision-making, and the use of tools such as Marine Spatial Planning (MSP) to understand how sustainability initiatives affect ecosystem health. MSP may also help detect issues, such as maritime traffic and trawling, and implement measures such as no trawl zones to enhance ecosystem health and catch potential. Additionally, cartography of littoral rocky-shore communities (CARLIT) can monitor ecological quality and infer conclusions indirectly on the impact of fishing activities.

Future management should take into account the vulnerability to thermal changes and the need to reduce conflicts between fishing fleet industries. Furthermore, artisanal fisheries along the Northern Adriatic Sea coast share similar features with other European areas, and future changes to the organization of the fishing fleet and the surrounding environmental conditions could lead to unsustainability in the future. Therefore, future management strategies should focus on sustainable harvesting and stock replenishment while taking into account the ecological and economic impacts of other marine sectors, to avoid uncontrolled increases in fishing and maintain the positive effects of the trawling ban. For the long-term benefit of all parties involved, it is critical to give priority to the preservation of marine ecosystems and to maintain a balance between environmental sustainability and economical benefits.


  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 Bastardie, Francois; Angelini, Silvia; Bolognini, Luca (February 2017). "Spatial planning for fisheries in the Northern Adriatic: working toward viable and sustainable fishing". Ecosphere. 8 (2). doi: Check |doi= value (help) – via Ecological Society of America.
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Lotze, H. K., Coll, M., & Dunne, J. A. (2010). Historical changes in marine resources, food-web structure and ecosystem functioning in the Adriatic Sea, Mediterranean. Ecosystems, 14(2), 198–222.
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 Carpi, Piera; Giuseppe, Scarcella; Cardinale, Massimiliano (December 2017). "The Saga of the Management of Fisheries in the Adriatic Sea: History, Flaws, Difficulties, and Successes toward the Application of the Common Fisheries Policy in the Mediterranean". Frontiers in Marine Science. 4. doi: Check |doi= value (help) – via Frontiers in Marine Science.
  4. 4.0 4.1 Matić-Skoko, S., Stagličić, N., Pallaoro, A., Kraljević, M., Dulčić, J., Tutman, P., & Dragičević, B. (2011). Effectiveness of conventional management in Mediterranean type artisanal fisheries. Estuarine, Coastal and Shelf Science, 91(2), 314–324.
  5. 5.0 5.1 5.2 Defranceso, Edi; Trestini, Samuele (2012). "An activity-based decision support system to evaluate the economic viability of fisheries management tools for the small pelagic species in the northern Adriatic Sea". Journal of Economics, Agriculture, and Environment. 11 (1): 12–18 – via ProQuest.
  6. 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 Carbonara, Pierluigi; Ciccolella, Alessandro; De Franco, Francesco (February 2022). "Does fish growth respond to fishing restrictions within Marine Protected Areas? A case study of the striped red mullet in the south-west Adriatic Sea (central Mediterranean)". Aquatic Conservation: Marine and Freshwater Ecosystems. 32 (3): 417–429. doi: Check |doi= value (help) – via Wiley Online Library.
  7. 7.0 7.1 "Gillnetting- how it works". Skipper Otto. November 6, 2020. |first= missing |last= (help)
  8. 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 8.11 8.12 Farella, Giulio; Tassetti, Anna Nora; Menegon, Stefano (24 January 2021). "Ecosystem-Based MSP for Enhanced Fisheries Sustainability: An Example from the Northern Adriatic (Chioggia—Venice and Rovigo, Italy)". Sustainability. 13 (3): 1211. doi: Check |doi= value (help) – via MDPI.
  9. 9.00 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 9.09 9.10 9.11 9.12 Nikolic, Vedran; Zuljevic, Ante; Mangialajo, Luisa (November 2013). "Cartography of littoral rocky-shore communities (CARLIT) as a tool for ecological quality assessment of coastal waters in the Eastern Adriatic Sea". Ecological Indicators. 34: 87–93. doi:10.1016/j.ecolind.2013.04.021 – via Elsevier Science Direct.
  10. 10.00 10.01 10.02 10.03 10.04 10.05 10.06 10.07 10.08 10.09 10.10 10.11 10.12 Luttenberger, L. R., Ančić, I., & Luttenberger, A. (2021, June 15). "The challenges for Croatian fisheries within current regulatory environment". Scientific Journal of Maritime Research. 35: 170–178 – via SRCE. Check date values in: |date= (help)CS1 maint: multiple names: authors list (link)
  11. 11.0 11.1 11.2 11.3 11.4 Fabio, P., Silvia, C., Paolo, V., & Monti, M. (March 2016). "Present and future status of artisanal fisheries in the Adriatic Sea (western Mediterranean Sea)". Ocean & Coastal Management. 122: 49–56 – via Elsevier Science Direct.CS1 maint: multiple names: authors list (link)
  12. Fortibuoni, T., Aldighieri, F., Giovanardi, O., Pranovi, F., Zucchetta, M. (2015). "Climate impact on Italian fisheries (Mediterranean Sea)". Regional Environmental Change. 15: 931–937 – via SpringerLink.CS1 maint: multiple names: authors list (link)
  13. Libralato, S., Caccin, A., Pranovi, F. (2015). "Modelling species invasions using thermal and trophic niche dynamics under climate change". Frontiers in Marine Science. 2 – via Frontiers in Marine Science.CS1 maint: multiple names: authors list (link)

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