Ali Cemal Gucu

Ecoregion-Based Conservation Planning in the Mediterranean: Dealing with Large-Scale Heterogeneity

Spatial priorities for the conservation of three key Mediterranean habitats, i.e. seagrass Posidonia oceanica meadows, coralligenous formations, and marine caves, were determined through a systematic planning approach. Available information on the distribution of these habitats across the entire Mediterranean Sea was compiled to produce basin-scale distribution maps. Conservation targets for each habitat type were set according to European Union guidelines. Surrogates were used to estimate the spatial variation of opportunity cost for commercial, non-commercial fishing, and aquaculture. Marxan conservation planning software was used to evaluate the comparative utility of two planning scenarios: (a) a whole-basin scenario, referring to selection of priority areas across the whole Mediterranean Sea, and (b) an ecoregional scenario, in which priority areas were selected within eight predefined ecoregions. Although both scenarios required approximately the same total area to be protected in order to achieve conservation targets, the opportunity cost differed between them. The whole-basin scenario yielded a lower opportunity cost, but the Alboran Sea ecoregion was not represented and priority areas were predominantly located in the Ionian, Aegean, and Adriatic Seas. In comparison, the ecoregional scenario resulted in a higher representation of ecoregions and a more even distribution of priority areas, albeit with a higher opportunity cost. We suggest that planning at the ecoregional level ensures better representativeness of the selected conservation features and adequate protection of species, functional, and genetic diversity across the basin. While there are several initiatives that identify priority areas in the Mediterranean Sea, our approach is novel as it combines three issues: (a) it is based on the distribution of habitats and not species, which was rarely the case in previous efforts, (b) it considers spatial variability of cost throughout this socioeconomically heterogeneous basin, and (c) it adopts ecoregions as the most appropriate level for large-scale planning.

Habitat use and preliminary demographic evaluation of the critically endangered Mediterranean monk seal (Monachus monachus) in the Cilician Basin (Eastern Mediterranean)

Over the last few decades a dramatic decline in the number of Mediterranean monk seals (Monachus monachus) limited scientific studies on the biology, behaviour, and ecology of the species. This lack of information impaired the effectiveness of conservation strategies. Thus, any further information gathered on the monk seal has utmost value in the work to halt and reverse the plight of the species. A hitherto unknown Cilician Basin colony of the Mediterranean monk seal has been investigated during a 6-year period between 1995 and 2001. Results of direct in-cave surveys and land based seal-watch observations enabled the evaluation of habitat use and preliminary demographic information. A total of 39 caves were discovered among which only three were used for breeding. Scarcity of the breeding caves emphasised the importance of breeding habitat in the survival of the colony. Common features of the breeding caves are found as an entrance with a protective barrier against strong waves; a chamber with a wide beach; and a well-sheltered shallow pool. Supplementary data obtained from infrared monitors installed in three actively used caves were used to assess the number of individuals. Throughout the study period, 25 individuals were identified and 11 newborn pups were found. Evaluation of the results suggests the presence of sub-regions inhabited by an individually identified sub-group of monk seals. Recommendations for conservation guided by this information is a Marine Protected Area consisting of two zones; a restricted core zone prohibiting any human activity securing breeding habitat and a restricted fishery zone securing sustainability of the food source.

Interaction between marine turtles and artisanal fisheries in the eastern Mediterranean: a probable cause for concern?

Abstract A survey of the levels of marine turtle bycatch in the small-boat based fisheries in northern Cyprus and the Turkish Mediterranean (Alanya to Mersin) was undertaken by questioning a sample of fishermen (n = 54) in all harbours in the survey region. Fishermen in Turkey caught an estimated 2.5 turtles/boat/year versus an estimated 4.0 turtles/boat/year in Cyprus. This yielded a likely minimum bycatch estimate of over 2,000 marine turtles per year in the region. An estimated 10% of turtles were thought to be dead at the point of capture. Turtles were caught in both nets and on long-lines and were perceived as detrimental to the livelihood of fishermen either by damaging nets, spoiling catch or removing bait. Although few fishermen admitted to deliberately killing turtles, a larger proportion thought others did so. Given the likelihood that a proportion of sea turtles caught will be Green Turtles (Chelonia mydas), and due to the highly endangered status of this species in this region, interaction wit...

Marine debris in bottom trawl catches and their effects on the selectivity grids in the north eastern Mediterranean

In this study composition of marine debris and their blocking potential on the selectivity grid systems deployed on demersal trawls were investigated in the north eastern Mediterranean. For this, a total of 132 hauls were examined in two fishing season between 20 September 2010 and 19 February 2012. Results showed that plastic items were the most abundant debris (73% in terms of weight) and they were followed by metals (10%). Because of plastics and packing debris, it is highly probable that grids may have been blocked in 85% of trawl hauls. The bathymetric and geographical variability in the quantity of debris were evaluated, and concluded that particularly in some areas where direction of currents and bottom topography favor deposition, such devices may easily be rendered ineffective by the plastics and packing debris in particular. To solve this problem, several solution proposals are submitted.

Role of Fishing in the Black Sea Ecosystem

The Black Sea anchovy has experienced the most severe decline of the past 50 years and the responsible factors are not yet clearly understood. This is mainly due to the possible existence of several factors which may be equally probable. Some of these factors are: the increased eutrophication which changed the oligotrophic character of the Black Sea into a dystrophic one; the introduction of ctenophore medusa, Mnemiopsis sp; the outstanding exploitation pressure of the over-capitalised fishing fleet, and alterations in river discharges and hydrologic conditions at the straits. In this study, the contribution of fishery to anchovy collapse has been evaluated. For this purpose, i) the increase of fishing power by the recent introduction of purse seiners and sonars and their effects on over-wintering stocks along the Turkish coasts, ii) the condition index as an indicator of starvation of anchovy for pre and post Mnemiopsis period, iii) the spawning behaviour of anchovy, and iv) the coexistence of anchovy and Mnemiopsis during the anchovy spawning season, have been reviewed. It was concluded that effects of over-capitalisation of the fishing sector, especially of Turkey, on anchovy collapse and to an extent on the catastrophic changes in the Black Sea ecosystem, should not be overlooked as secondary.

Occurrence of the critically endangered Mediterranean Monk Seal, Monachus monachus, at Olympos-Beydağları National Park, Turkey (Mammalia: Phocidae)

Abstract The coast of Antalya, despite being acknowledged as an important Monk Seal (Monachus monachus Hermann, 1779) habitat, has never been studied systematically for the occurrence of the species. The rocky cliff-bound coast of Antalya Olympos-Beydağları National Park, where human disturbance appears minimal compared to the rest in the area, was surveyed between June and November 2008. Of the 39 caves discovered, both along mainland and island coasts, only 8 were considered suitable for placing photo-traps and a total of 11 automatic cameras was deployed. The caves were periodically visited to retrieve recorded digital images. 4 individual seals (2 adults, 2 juveniles) were photo-identified in 3 caves. The National Park provides suitable habitat for breeding. Human disturbance was very high throughout the Monk Seal habitats, and the most serious pressure appeared to be the human intruders in the caves. From the conservation point-of-view, three sites in the surveyed area, Üçadalar, Olympos and Adrasan, were noted as significant and so require strict protection.

Spatial distribution of the Black Sea copepod, Calanus euxinus, estimated using multi-frequency acoustic backscatter

Spatial distribution of the Black Sea copepod, Calanus euxinus, estimated using multi-frequency acoustic backscatter Serdar Sakınan,* and Ali Cemal Gücü Institute of Marine Sciences, Middle East Technical University, P.O. Box 28, Mersin 33731, Turkey Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA *Corresponding author: tel: þ90 324 5212406; fax: þ90 324 5212327; e-mail: serdar@ims.metu.edu.tr