Conserving mobulas under fire

This project aims to undertake an assessment of the scale of the seasonal mobulid fishery in Gaza, Palestine. This will include the collection of biological, ecological and socio-economic data.

Recent images and reports have revealed a targeted fishery for the giant devil ray, an endangered species, in Gaza. We need to collect data now before this ray is pushed to the point of collapse.

The giant devil ray occurs in deep, offshore waters and occasionally in shallow waters throughout the Mediterranean Sea. Until now there were not thought to be any direct fisheries for giant devil rays, although high mortality rates have been reported for this species when its caught accidentally in pelagic driftnets targeting swordfish in the Mediterranean. Giant devil rays are also accidentally captured in long-lines, purse seine nets, trawl nets and fixed traditional tuna traps. They are also occasionally caught as by-catch in the western central Ligurian Sea, where long-line catches have been monitored since 1999.
The giant devil ray is included in Annex II of the ‘List of endangered or threatened species’ to the Protocol concerning Specially Protected Areas and Biological Diversity in the Mediterranean of the Barcelona Convention, which came into force in 2001. Recent regional legislation has introduced new basin-wide bans of pelagic driftnets; if implemented, this would eliminate one of the most severe threats to the species.

The aims and objectives of this project are to:

• Collect data on mobulid rays from fish landing sites in Gaza.
• Identify the fishing methods used and the seasonality of this fishery.
• Estimate the scale and sustainability of the Gaza mobulid fishery.
• Collect information on the gill plate trade and the value of mobulids for the local economy.

Results summary:

Throughout the months of April 2017 to March 2018, all elasmobranch landings were recorded from the 8 major landings sites, along with data on dimensions, weight, sex, and sexual maturity, along with the recording of specimens using digital photographs. DNA samples were also collected and sent for analysis. Information was collected using a detailed questionnaire and interviews with 90 commercial fishers to learn about the past and current shark and ray catches, perceptions of shark fisheries and past and current fisheries catches.

Interviews were conducted with fishers, consumers, fish dealers and other officials working in the fisheries sector to better understand the past and present fishery dynamics. Specifically, we asked about gears, catches, personal viewpoints, key fishing grounds, market values, product usage and the export trade. To teach marine ecology and conservation awareness to fishers and to school children, several intensive and passionate conservation awareness and outreach workshops were conducted, which highlighted the following topics to both fishers and school children.

Topics covered included our project’s aims, the importance of top predators, threats facing elasmobranches, negative fishing practices, and the importance of tagging to benefit our understanding of Mobulids. Three government members also participated in these awareness workshops.

Current and proposed conservation strategies

All fishers interviewed in Gaza were unaware of the ‘Endangered’ status of Mobula mobular and the Mediterranean-wide protection of this species. When interviewed by one of our team to gain a better understanding of the fisheries, each fisher was made aware of Mobula mobular’s ‘Endangered’ status and need for protection. In addition, posters relaying the same information have been displayed at local fish marketsvexplaining the need for Mobula mobular conservation. All species of Mobula were included on CITES (Convention on International Trade in Endangered Species of Wild Flora and Fauna) Appendix II in 2016. This ensures that any global trade taking place is done so with the appropriate export permits certifying that trade is non-detrimental to the health of the stocks. However, Palestine is not a signatory to CITES, and when trade is reinstated, this lack of protection could potentially increase the threat to the conservation of this species. As Mobula mobular only frequents Palestinian waters for a very short period each year, only a few dozen purse-seine fishers directly benefit from the Mobula mobular catches. While it is understood that the first priority of Palestinian fishers is to meet their basic needs, this implies that in order for fishers to willingly forgo this opportunistic target fishery, some form of compensation will be required.

Considering there are only 1,100 purse-seine fishers, and only a few dozen that directly benefit from target Mobula mobular catches, the total sum required to compensate these purse-seine fishers would be quite low. In addition to restricting the target fishery, it is recommended that regulations be introduced to encourage the release of specimens caught as bycatch, and educational programs be run to address the lack of awareness with regard to the status of species. To combat the unawareness matter, community outreach has been initiated with school children, fishers and government officials in Gaza to promote conservation awareness for Mobula mobular. However, future protection of this species at the national scale will likely require a more creative solution (i.e., by first ensuring nutritional requirements are met) than just conservation education and awareness alone, as trade restrictions combined with loss of employment have had a serious impact on food security.

In conjunction with monitoring the Palestinian Mobula mobular fisheries, all elasmobranch catches are being recorded to learn of other locally endangered species possibly needing further protection, as one in four elasmobranchs worldwide are currently threatened with extinction, mostly stemming from fishing alone (Ward-Paige et al. 2013), and the situation is even more severe in the Mediterranean Sea (Dulvy et al. 2014). This work specifically contributes to the enrichment of several objectives in the ‘Global Devil Ray and Manta Conservation Strategy’, such as helping to understand growth, fisheries drivers, and fisheries assessment (Lawson et al, 2017). Closer collaborations between scientists should also be promoted in order to better understand the Mediterranean Mobula mobular populations.