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Project C.4.b - Long-term sampling program for shark catches of artisanal fisheries in Central America: Phase 1

01 Apr 2020 - 31 Dec 2021

Completed
Program(s) in charge: Stock Assessment Program
Funded
Objectives
Conduct Phase 1 (1st year) of a long-term sampling program of shark catches by
artisanal fisheries in Central America, using sampling methods and logistics developed
under the extended FAO-GEF project.
Background
  • Assessment modelling for shark species in the EPO is severely hampered by a lack of reliable data on shark catches.
  • Previous work by IATTC staff identified specific data gaps and data collection needs, including the critical need for catch data from Central American fisheries, some components of which are believed generate a large fraction of the EPO catches of sharks.
  • The current FAO-GEF-funded project on developing sampling designs for the composition of the shark catches by artisanal fisheries in Central America, supplemented with IATTC capacity-building funds, will be completed at the end of 2019.
  • This extended FAO-GEF project has generated, and continues to generate, a wealth of information with which to develop sampling designs for various fleet components of Central American coastal fisheries that land sharks (SAC-10-16).
  • However, no funding is available to implement a long-term sampling program using the methodology developed under the FAO-GEF project.
  • Without data provided by a properly designed long-term sampling program for Central American artisanal fisheries, the IATTC will not be able to meet the goal of Resolution C-16-05 of EPO assessments of silky and hammerhead sharks.
  • Phase 1 of the long-term sampling program will provide the necessary extensive field testing required to fine-tune sampling methodology, logistics and costs for Phase 2 (regular sampling).
Relevance for management
Data collected under a long-term monitoring program based on fully-tested sampling designs will allow for development of stock status indicators and conventional assessments of key shark species
Duration
21 months
Workplan and status
2021: Implement the sampling designs developed under the extended FAO-GEF project.
External collaborators
OSPESCA, Central American national authorities
Deliverables
  • Sampling designs and logistical plans for estimating the species and size composition of shark catches in Central American artisanal fisheries.
  • IATTC-98-02c (2021): report on final sampling design methodology and costs.
Updated date: 01 May 2022
Progress summary for the reporting period
March- 2020 to March 2021
  • The COVID-19 quarantine resulted in a 5-month delay to start this project (March to July 2020).
  • After issues related to the pandemic were resolved, the sampling program began in August 2020, at which point 14 sampling technician and two data editors were hired.
  • After January 2021, the sampling methodology changed, and field workdays increased as COVID-19 restrictions were reduced and businesses such as hotels and restaurants on shore opened.
  • As of the beginning of March 2021, a total of 1,300 vessels were sampled. The samples contained a total of 1,986 fish, of which 49% were sharks and 28% rays, the rest of the sampled fish were dorado, billfishes and tunas. Also reported were juveniles of manta species (Fam. Mobulidae), pregnant thresher sharks, and others.
  • New task: with the collaboration project between The Manta Trust, The Monterey Bay Aquarium, The Conservation Action Lab at University of California Santa Cruz, and the Inter-American Tropical Tuna Commission (Project M.2.c), opportunistic tissue sampling started in March 2021 for mantas and devil rays to better understand their population structure.
April-June 2021 
  • Around 1,000 records were collected in this period. The most important species group reported was sharks (53%), followed by rays (24%), dorado (11%), billfishes (4%), and tuna (7%). The main shark species were silky sharks and hammerhead sharks.
  • 65 tissue samples were collected for mantas and devil rays in Nicaragua (85%), Guatemala (15%); all samples from Nicaragua were delivered to the Conservation Action Lab at the University of California Santa Cruz (UCSC).
July-September 2021 
  • As of September 2021, a total of 4,190 samples were registered. The number of samples in this period was higher than at the beginning of the project (>1,200 samples). As a result, the catches of dorado and rays increased to 18% and 26%, respectively, and shark catches decreased by 42%.
  • 77 tissue samples were collected for mantas and devil rays in Nicaragua and were delivered to UCSC for analysis.

October-December 2021
  • The number of records decreased in this period (<800 samples). The catches of sharks and rays decreased compared to the last period, to 33% and 19% respectively, but dorado catches increased (30%).
  • A total of 4,964 samples were registered; these data were distributed in order of the number of samples: Nicaragua (38%), Panama (28%), Guatemala (14%), El Salvador (13%), and Costa Rica (6%). The countries with the highest distribution of large pelagic catches was Nicaragua (61% sharks, 24% dorado, 11% billfishes, and 4% tuna); followed by Costa Rica (64% sharks, 20% dorado, and 8% billfishes and tuna); El Salvador (69% sharks, 15% dorado, 11% billfishes and 5% tuna); Guatemala (82% sharks, 10% dorado, 1% billfishes and 6% tuna); and the catch of sharks and related species in Panama had the least interaction with others large pelagic species (97% sharks, 1% dorado, and 1% tuna).
  • Because the project was nearing completion (December 2021), sampling days were reduced in the last month. The sampling technicians worked in the field until 15 December. The remaining days were used to prepare the final report.
  • All the tissue samples from Nicaragua and Guatemala have been sent to UCSC for analysis. The staff is in process of obtaining CITES permits to export the samples from Ecuador at the moment.
Challenges and key lessons learnt
  • Due the pandemic, numerous issues were encountered related to all data collection, which varied by country; in particular, there was a ban on fishing activity in areas with the potential for a high density of fishers and buyers. Also, size composition sampling had to be suspended to avoid close contact between fishers an samplers . However, these issues were overcome as the COVID-19 pandemic regulations became less restrictive, so sampling days and biometric data collection increased.
  • The effects of the pandemic are evident, with the number of pangas changing considerably at many sites. Although 2020–2021 catch rate data are still being analyzed, preliminary results indicate that sites where catches of silky shark and hammerhead sharks were identified from the fisher interviews in 2019 as primary and secondary sites seem to actually operate as tertiary sites (no catch of those sharks) or vice-versa.
  • Lennert-Cody, C.E., Mccracken, M., Siu, S., Oliveros-Ramos, R., Maunder, M.N., Aires-da-Silva, A., Carvajal Rodríguez, J.M., Opsomer, J., Barros, P., 2022. Single-cluster systematic sampling designs for shark catch size composition in a Central American longline fishery. Fisheries Research 251 (2022) 106320, p. 14. https://doi.org/10.1016/j.fishres.2022.106320
  • Oliveros-Ramos, R., Lennert-Cody, C.E., Siu, S., Salaverría, S., Maunder, M.N., Aires-da- Silva, A., 2019. Pilot study for a shark fishery sampling program in Central America. Inter-Am. Trop. Tuna Comm. Doc. SAC-10-16.
  • Oliveros-Ramos, R., Lennert-Cody, C.E., Siu, S., Salaverría, S., Maunder, M.N., Aires-da- Silva, A., Carvajal Rodríguez, J., 2020. Pilot study for a shark fishery sampling program in Central America. Inter-Am. Trop. Tuna Comm. Doc. SAC-11-13.
Comments
The project concluded in December 2021. Unfortunately, it was not possible to obtain financial support from the Members for its continuation.