Adriatic-Ionian Transboundary Conservation


The Adriatic-Ionian Region (AIR) is an important maritime region for Europe and provides a challenging case study for the identification of a basin-wide marine spatial plans strategy, specifically due to the differences in approaches, government and governance structures between AIR coastal countries. The current EU Integrated Maritime Policy specifically recognizes the importance of cooperation at the sea-basin level, and suggests that the best results will be achieved through developing marine spatial plans at national and cross-border levels. The Adriatic and Ionian Region is an important area for both strategic maritime development and biodiversity conservation in the European Union (EU). However, given that both EU and non-EU countries border the sea, multiple legal and regulatory frameworks operate at different scales, which can hinder the coordinated long-term sustainable development of the region. Transboundary marine spatial planning can help overcome these challenges by building consensus on planning objectives and making the trade-offs between biodiversity conservation and its influence on economically important sectors more explicit. While EU member states have been called to integrate their maritime spatial plans into a transboundary approach by year 2020, there is no clear direction on how to put this into practice. We sought to demonstrate how to simplify the highly dynamic, multiactor, multiscalar, multinational challenge of developing a strategic transboundary marine spatial planning framework for the AIR using a marine spatial conservation prioritization approach.
We constructed 4 planning scenarios by varying the geographical scope at which conservation targets were set in combination with the 2 treatments of costs (table 1). We applied conservation targets at 2 scales: for the distributions of features across the entire AIR and for each feature's distribution inside the jurisdiction of AIR countries (Albania [AL], Croatia [HR], Greece [GR], Italy [IT], Montenegro [MT], and Slovenia [SL]). The disputed marine waters between Croatia and Slovenia (disputed area [DA]) were considered as an independent geographical area. We treated cost in 2 different ways with common proxies: i) the area of each planning unit as the baseline cost, meaning targets are met with the smallest possible spatial footprint, and ii) the number of maritime industries occurring in each planning unit as a proxy for the transaction costs of negotiating biodiversity protection in each unit (e.g., the more industries, the higher cost to conserve).

We also analyzed scenarios with the proportional protection equality (PEP) metric (Chauvenet et al. 2017). Proportional protection equality evaluates how equally represented features are in a conservation. We calculated PEP based on the proportion of AIR countries’ jurisdiction and the distribution of each maritime industry captured in solutions for each scenario.

Influence of Regional Versus National Target Setting
When conservation targets were assigned by country, the number of features in the analysis increased from 70 to 263. This had little influence on the area of the conservation footprint required to meet these additional targets in the best solutions (with an average of 16.8% of the area in the AIR for scenario 1a, 17.1% for scenario 2a, 18.3% for scenario 1b, and 19.1% for scenario 2b). The greatest impact of setting targets at the national level occurred when industry costs were also included (scenario 2b). This increased the total cost of the network by 20% with a marginal increase in total area compared to setting targets across the AIR (scenario 1b).
Priority areas for conservation
Under the objectives of the European Union Strategy for the Adriatic Ionian Region, marine spatial planning processes are underway to balance maritime development with biodiversity objective, yet coordination across jurisdictions remains a major challenge. We demonstrated how decision‐support tools can help harmonize the needs of both nature conservation and maritime industries within the complex AIR seascape through spatial conservation prioritization.

The distribution of priority areas for conservation (i.e., the planning units with highest selection frequency) varied significantly across our 4 scenarios (Fig. 1). When cost was assigned as the area of the planning units, regardless of the target‐setting strategy, solutions were very flexible, with almost 98% of the AIR included at some point (Figs. 1a & 1c). When we accounted for industries operating in the AIR by including them as a cost (scenario 1b, 2b), the resulting solutions became more spatially decisive and 25% of the AIR was never selected (Figs. 1b & 1d). When we accounted for industry costs, the results identified priority areas around the presence of spatially constrained biodiversity features. These areas include the central areas of the Northern Adriatic, where Mullus barbatus (red mullet) spawn; the central Adriatic between Italy and Croatia, where Eledone cirrhosa are preferentially present (horned octopus) and Nephrops norvegicus (Norway lobster) spawn; the coastal areas of Albania, where Aristaeomorpha foliacea (giant red shrimp) spawn and recruitment occurs and Galeus melastomus (blackmouth catshark) recruitment occurs; and the coastal areas of Greece, where monk seals, whales, and turtles nesting sites occur and Raja clavata (thornback ray) spawn.

Trade-offs need to be made explicit
Understanding trade-offs is an essential component of spatial conservation prioritization and can greatly influence planning success. Through the protection equality metric, we found that countries maintained a high level of equality regardless of the scenario (Fig. 2a), but protection equality across industries was significantly lower (Fig. 2b) and more variable across scenarios. This can be partially explained by our construction of the industry cost proxy and its use in the Marxan objective function. The method of including costs has significant implications for evaluating trade-offs that are critical to decision making and their treatment should be carefully considered.
Selection frequency for 4 marine conservation prioritization scenarios: (a) scenario 1, planning at the regional scale with area of the planning unit as the baseline cost (i.e., targets met with the smallest possible spatial footprint); (b) scenario 1b, planning at the regional scale with the number of maritime industries in a planning unit as the cost of a planning unit; (c) scenario 2a, planning at the country scale with area of the planning unit as the baseline cost; (d) scenario 2b, planning at the country scale with the number of maritime industries in a planning unit as the cost (AL, Albania; BE, Bosnia‐Herzegovina; GR, Greece, IT, Italy; MT, Montenegro; SL, Slovenia).


Gissi, Elena, et al. "Addressing transboundary conservation challenges through marine spatial prioritization." Conservation Biology 32.5 (2018): 1107-1117.
Contact Information:
Elena Gissi

Elena Gissi

Senior researcher, Marie Sklodowska Curie Fellow, National Research Council, Institute of Marine Sciences, Venice, Italy, and Stanford University, Hopkins Marine Station, USA