Agnese Mancini

Dead cormorans in fishing nets

Since the beginning of May, the number of stranded animals on the monitored beaches raised pretty much. Even if Proyecto Carapacho is focusing on sea turtles mortality causes and rates in Baja California Sur, we also started
counting stranded marine mammals as sea lions, dolphins, whales and seals because of the increasing number found on the monitored area. From our findings, bycatch is a threat in Baja California Sur not only to sea turtles but also to other species. 59 dolphins were found stranded, according to external marks (i.e. cut fins, scars), their death is mostly related to incidental fishery. For sea lions (54 individualscounted) and seals (3 individuals), death cause is harder to determine. We also found at least 80 cormorans entrapped in fishing net, we could rescue just one the others being already dead when we arrived (see pictures).

Concerning sea turtles, a total of 160 carapaces have been counted: 36 were consumed (mostly during lent time), 50 stranded for unknown reasons and 74 died incidentally in fishing nets. The relationship with artesanal fishery is pretty evident especially in SanIgnacio lagoon where strandings are frequent only in correspondence with the guitarfish fishing season. “The problem is
that most of the people that are fishing within the lagoon are not allowed to but as law enforcement is very low,illegal fishers are throwing their nets in the channels catching incidentally large amounts of sea turtles” said Ranulfo Mayoral, member of the Grupo Tortuguero from San Ignacio. A meeting was organized and the presence of the authority was required for the next season in order to discourage illegal fishers in the area.

Study area. Communities have been divided into three profiles depending on the features of the sea turtle black market.

During the last two months very few carapaces have been found stranded on beaches or in dumpsites. With respect to the same period the past year (when we found more than 200 turtles), this is a really good news. We could then focus on interviews with fishermen and people from the community to trace a profile of all the communities we are visiting.

We conducted more then 150 interviews and could divide the communities into three profiles (see map
attached):
- red: communities where there still is a network of sea turtles hunters.These people are organized in solid networks and live of the earnings from this activity. Proper “Sea turtle hunters” have disappeared, most of these people are dedicated more generally to the illegal fishery;
- green: communities where there still is a developed local market. Mostof the fishers also catch sea turtles when they are asked for or during bad fishing seasons to have an extra-income. Sea turtles are sold only in the
community and are not exported;
- blue: communities where the market has disappeared but there still is local consumption. Sea turtles are caught to celebrate special events and are shared among friends and family.

This preliminary description is useful to give us an idea of what the problem really is in every community and allow us to implement specific conservation measures adapted to each community.

In January 2008 Proyecto Carapacho took part at the 10th annual meeting of Grupo Tortuguero. During this conference we had the chance to thank all the fishermen and community members that are supporting our project.

We also had the chance to present a poster (see figure 1) and two oral presentations at the 28th International Sea Turtle Symposium that took place in Loreto, BCS. During this international meeting we could share main results of our work with researchers from all over the world and we received very good comments on how to improve our work.
Concerning sea turtles, we recorded a massive mortality in Laguna Ojo de Liebre, probably due to a sudden decrease of sea temperature. Further investigations are still undergoing, jointly with the Mexican agency for the protection of the environment (PROFEPA).

From March to April 2008 we continued monitoring beaches on both the Pacific and the Gulf coasts. Very few sea turtles have been found stranded, nevertheless we found an increasing number of sea lions and dolphins. We also found 5 stranded grey whales, which death cause is still unknown.

During Holy Week we increased our talks and interviews with community members as during this period sea turtle consumption usually increases dramatically. Even if we could not find evidence of such consumption, through interviews we learnt that it still is very common to eat sea turtle meat, considered the best substitute for red meat.

Sea turtles drowned in gillnets.

Between May and June we focused our attention on a specific site: San Ignacio Lagoon. Located on the on the Pacific coast of the state of Baja California Sur and covering an approximate area of 17,500 ha, the lagoon is located at the southern end of the Vizcaino Biosphere Reserve. It was declared World Heritage site by UNESCO in 1993 and Ramsar site in 2004.The lagoon is a very important feeding and growing site for the East Pacific green turtle (Chelonia mydas). During 2006 and 2007, we recorded a rise in sea turtle strandings possibly related to high bycatch rates. This year we spent more time in the lagoon to observe and document the problem. We counted more than 100 dead turtles both stranded on the beach and floating.

The main cause for this massive mortality event is the incidental fishery in nets used for the guitarfish. Gillnets are thrown in the main channels and checked every 24h. Turtles use the channels to move inside the lagoon and get
usually entangled and die if not freed in the following 1-2h. The problem is that fishermen working inside the lagoon are fishing illegally for two main reasons: they do not have the proper permit to catch guitarfish, furthermore since 2007 Mexican law forbids shark and ray fishery inside bays and lagoons as these areas are used as reproductive and nursery habitat. This fishery usually takes place for 7 to 10 days and at least 10-15 equipments are involved. We estimated that total mortality in june 2008 was around 400 – 600 turtles every year. We invited kids from local communities and worked with them to monitor the beach and spread knowledge about thi situation.