Since the mid 90´s, Pretoma has worked in a number of different coastal communities along the Pacific coast of Costa Rica. Pretoma´s work started with the initiative to conserve marine turtles on important nesting beaches located along the coastline. However over time it became clear that by only protecting marine turtle nesting beaches this would not guarantee there complete protection, as there exists a high negative interaction between commercial fisheries and the turtles feeding and mating grounds and their migratory routes. This is when Pretoma started working alongside the local fishermen collecting data, which providing information regarding the capture of turtles and other non-commercial species in relation to the type of fishing gear used.
The first investigations that Pretoma initiated were with shrimp trawlers, to evaluate the efficiency of using TED´S turtle excluder devices in the incidental capture of marine turtles during Trawling.
By 2004 Pretoma had made countless trips onboard shrimp trawlers testing the TED´S efficiency, during the same year the inventor of the TED and shrimp fisherman Sinkey Boone repeatedly visited Puntarenas to share his knowledge and to help implement the Tico TED.
Since 1999 Pretoma has had an observer program onboard longline fishing boats, through the support of the company sea food Papagayo in Playas de Coco, it has been possible to execute more than 30 trips onboard evaluating the incidental capture of sea turtles by the long line fisheries industry.
The local artisanal longlining fleet comprises of approximately 330 boats built of steel and fiberglass, each boats length varies between 10 and 13 meters and has a holding capacity of between 1 and 6 tons of catch. The fuel tanks have a moderate capacity that does not exceed 600 gallons and are powered with engines ranging from 30 to 120 HP.
Each boat is equipped with a mother line which can be up to 40 miles in length with a capacity to hold a maximum of 1500 hooks. The limited autonomy for these vessels does not permit them to travel safely out to 200 miles from the coast.
In general, each fishing trip has duration of 2 weeks. However due to lower catch rates there is now a higher necessity to travel greater distances, up to 800 miles in order to find good fishing grounds which extends the trips significantly. It also carries a higher risk as extra fuel tanks are loaded on the work deck causing risk to the stability of the boat and therefore to the crew members.
Pretoma has also been conducting research with the Artisanal Fisheries, within the fishing communities Guiones, Tárcoles, Bejuco y Coyote all located on the Pacific coast of Costa Rica. In Guiones we evaluated the interaction between marine turtles and the artisanal fisheries within the marine protected area of Guiones, while in Tárcoles we evaluated and analyzed the capture of sharks and rays by these local fishermen.
Currently within the Caletas-Arío refuge we conducting research which aims to promote responsible fishing of red snapper, (Lutjanus guttatus), which are captured by the local fishermen of the area. The towns of Coyote y Bejuco are looking to become the first two areas to obtain certification for responsible fisheries at an international level.
The local artisanal fishing in the southern coast of the Nicoya peninsula was established approximately 25 years ago, (We used to throw 300 hooks and fish for 3 hours, we would catch a large quantity of fish now we throw 1000 hooks and sometimes do not catch enough fish to pay for the gasoline to get back and forth from the fishing grounds, explains, dice Amado Quirós, Artisanal fisherman of the area), There are now approximately 100 families within the area that depend upon the local fisheries.
The fishing grounds in which the local artisanal fishermen use are being constantly being invaded by semi-industrial shrimp trawlers and other destructive forms of fishing such as gill netting, compressor diving principally for lobster and lines used to capture rays. All of these types of fishing have the capacity to extract the oceans resources in an unsustainable manner.
During the last few years Pretoma has monitored fishing operations onboard the small boats and during unloading at the docks and have monitored the total catch per month from each fishing community, This has been done in order to obtain a responsible fisheries certification for the artisanal sector, and to improve and increase the Price of their products within the market, and to ensure the existence of marine and coastal resources for the future.
Bottom Line: Consists of a main line laid n the sea bed which has a branch line every 3 meters containing 7-8 hooks, Sardines are the main form of bait used by these fishermen. The small boats are approximately 18 feet in length and use a 30 to 50 horsepower engine. Fishing is done at night beginning late in the afternoon and returning to dock early in the morning.
This type of fishing is focused on catching spotted snapper, (lutjanus guttatus) along with a few other commercially important species such as yellow tailed snapper, corvinas, and groupers. Although most of the fishermen are primarily men women and children are also involved in the process by preparing the lines adding hooks and bait.
Recently with the support from the local fishermen and authorities we have created two marine protected areas, mixed wildlife refuge of Caletas-Ario and Wildlife refuge of Camaronal having 19000 and 16000 hectares of protected marine area respectively. Within these refuges there are only limited forms of fishing allowed, these include Artisanal line fisheries, hand line, diving for lobster and sport fishing.
Pretoma’s other fisheries projects. Pretoma studies the incidental capture of marine Turtles during commercial operations of long liners in Playas del Coco, Costa Rica. This fleet utilises circular hooks #14 y #15, with a deviation in the hooks point, and varying bait such as squid, black tuna (Katsuwanus pelamis),, sardines and thresher shark, (Alopidae). Throughout the years we have documented a catch per effort unit weight averaged between 4.75 – 10.71 individuals/1000 hooks (min. = 0, max. = 58.26). The fleet consists of over 500 vessels using over 700,000 hooks we have estimated the annual catch of marine Turtles to be approximately 300,000, (Arauz et al, 2007).
Pretoma’s investigations to mitigate the impact of pelagic fishing on marine turtles started with the use of blue bait to reduce their incidental capture. However, this technique did not demonstrate any efficiency in longline fisheries in Costa Rica where the main turtle captured is the Olive ridley (Lepidochelys olivácea) (Swimmer et al, 2005). We also modified the tip deflection to 10° (offset) in circular hooks #14, however this also did not have a positive impact n the levels of captured sea turtles in Costa Rica (Swimmer et al, 2010).
The research involved the presence of Pretoma observers onboard long line vessels in Playas del Coco, to introduce technology that permits the release of marine turtles by causing the least possible damage, enabling the study of post harvest mortality of sea turtles using satellite tracking, and evaluate the efficiency to modify the bait to use blue bait which was compared statistically.
Bull shark project in the Sirena River. (February and July, 2009)
The bull shark is a coastal benthic species common in waters close to estuaries and river mouths in tropical and subtropical areas, Adult sharks are commonly observed around coastal islands close to the continental shelf.
In the Sirena river mouth, within the national park of Corcovado bull sharks are commonly observed, within the river month when the tide is rising. There is currently an area of 500 meters along the coast of the national park where fishing operations are restricted however limited authority within the area makes it difficult to know if the area is monitored sufficiently to ensure the protection of these bull sharks.
The objective of this project is to monitor the movements of the bull sharks within the river mouth, by using acoustic telemetry, and assist the authorities of the ministry of environment with the design of new policies aimed at conservation and management. We also hope to collect morph metric information, reproductive status of males and genetic sampling.
Modified hook Project
To assist in the restoration of marine turtle populations in the region Pretoma is studying methods to mitigate the impact of Costa Rican long line fleets, either by reducing the rates of interaction and or methods to release turtles properly from the hooks without causing lasting damage. In this particular investigation we wanted to assess the efficiency of “alternative” and “liberating” hooks regarding the release of marine turtles, retention of commercially valuable species and impact on other marine species. All hooks are designed to facilitate the release of marine turtles from hooks without the need to load the animal onboard the vessel.
The objective is to value the efficiency Pretoma two models of modified hooks (hook Wilber alternative Acosta and UH-releasing hook – Pretoma) in the capture and release of sea turtles and retention of other commercial species and bycatch during longline fishing Golfito.
The recommended technique to release a captured turtle to increase its chances of survival requires that it is to be brought onto the vessels and the hook dislodged by cutting the hook out or using a D-hooker (Swimmer et al, 2006). However bringing a turtle onboard the vessel causes physical exertion especially when dozens of Turtles are caught on the same line, it is also common that the fishermen cut the line and leave the hook on the turtle which causes serious injury and death, reducing the benefits of using a circle hook.
Our results to date have indicated that “liberating” hooks capture the same amount of commercial species tan the normal hook, this is positive as it indicates that the fishing for commercial species is not effected, it also proved that Turtles can be released easily without the need to bring Turtles on board the vessels along with other species of no commercial use such as rays which are frequently caught.
Pretoma continues testing new fishing technologies to lower the impact n the decreasing populations of marine Turtles and sharks in the Pacific.