Tag: data

Ensuring better fisheries management in West Africa

This week, the Sea Around Us Project’s Principal Investigator, Daniel Pauly, and one of our PhD students, Dyhia Belhabib, attended the Regional Marine and Coastal Forum held in Dakar, Senegal, where representatives from eight West African countries gathered to discuss the status of fisheries in the region and their future. Their goal was to engage the countries in tackling unreported fishing.

By working with researchers at the Sea Around Us Project to assess their fisheries from 1950 to 2010, these countries have identified the extent of unreported fishing in their waters – which is often as much as double what is officially reported.

“Fishing operations in West Africa have been catching much more than anyone previously realised and reported,” says Dyhia Belhabib. “The research we are conducting in partnership with West African countries gives them the first complete historical picture of their fisheries.”

In response, some countries in the region have started to take steps to address the gaps and improve fisheries management. In Senegal, the government has developed a fisheries commission and signed an agreement to improve the current reporting and management of its fisheries.

“This joint research is shedding new light on the true extent of past fishing in West Africa,” says Daniel Pauly. “Our hope is that these countries will now adopt the results and use them to contribute to better fisheries management in the future.”

You can read the complete press release in English and French here.

ELEFAN in (Daka)R

Participants

During June, Deng Palomares and Daniel Pauly spent a week teaching a newly updated version of the ELEFAN software at the Institute for Fisheries and Aquaculture of the University Cheick Anta Diop of Dakar, Senegal. (Photo: Najih Lazar)

by M.L. ‘Deng’ Palomares and Daniel Pauly

The ELEFAN software and approach for the estimation of von Bertalanffy growth parameters from length-frequency data was developed at the International Center for Living Aquatic Resources Management (ICLARM), in Manila, Philippines, in the early 1980s by Daniel Pauly and two programmers (Noel David and Felimon Gayanilo). It was disseminated in various versions throughout the world, especially in tropical countries, through a series of training courses during the 1980s and 1990s. It also formed the core of a comprehensive software package called FAO-ICLARM Stock Assessment Tools (FiSAT; [1], [2]), still available from the FAO.

Overall, about 5,500 papers based on the ELEFAN approach, as incorporated in FiSAT and its predecessors have been published in the past 30+ years (as identified by Google Scholar records with “ELEFAN” in the title or the body of the text). However, since its release, FiSAT has been updated only once (FiSAT II; [3]), and it has become outdated in content and form. Thus, the offer was accepted to collaborate with USAID’s COMFISH Project in Senegal to produce an updated version of ELEFAN and to test it in a training course in Dakar before releasing it for wider use as open-source software.

The bulk of the R coding was completed by Aaron Greenberg (with Mathieu Colléter also contributing a routine) just in time for a team consisting of Ted Hart (of UBC’s Biodiversity Research Centre), Danielle Knip and Deng Palomares (of the Sea Around Us Project) to create a stand-alone package copied on 25 USB sticks at the end of May.

Daniel Pauly and Deng Palomares then spent a week in an ELEFAN training course, held at the Institute for Fisheries and Aquaculture of the University Cheick Anta Diop of Dakar, teaching the routines behind and the functioning of the ELEFAN package. The group of 25 Senegalese participants consisted of about one-half fisheries scientists and graduate students, and the other half of fisheries inspectors.

While the fisheries inspectors struggled somewhat with the relevance of growth and mortality estimations and clearly preferred Daniel’s lectures on fisheries and climate change issues, the students and scientists benefitted greatly from this training workshop and generated – with Deng’s help – results for sardinella (Sardinella aurita, S. maderensi), white grouper or thiof (Epinephelus aeneus), bonga (Ethmalosa fimbriata) and other species. The results – to our relief – were comparable to those obtained by a group of colleagues (also working for the COMFISH Project) through tedious reading of annual rings on bony structures. Indeed, in the case of octopus (where the cubic root of the weight was used instead of length), results were obtained which could not have been obtained though ageing of bony structures – octopi
have no bones…

Thus, overall, the personnel who had arranged the workshop, notably COMFISH Project Leader Chris Mathews and Najih Lazar, Technical Advisor, both of The University of Rhode Island, were as pleased as we were about both the knowledge that was passed on during the workshop and the performance of the trial version of ELEFAN in R. Obviously, a number of items were noted which require improvement, as well as a swarm of bugs, both of which are due to be fixed in the next two to three months. The high hopes that we have for this new release of ELEFAN in R appear justified.

Daniel used the opportunity of being in Senegal to visit the Département des Pêches Maritimes, where he briefed its Director, Mr. J.-P. Manel, and members of his senior staff on the results of the reconstruction of Senegalese marine catches led by Dyhia Belhabib, with support from the MAVA Foundation and co-authors from the COMFISH project (Ms. Vivianne Koutob), the DPM (Mr. Lamine Mbaye) and WWF-Senegal (Mr. Nassirou Gueye). It was very gratifying that our Senegalese partners acknowledged that they have catch-reporting problems, both with regards to substantial illegal fishing in Senegalese waters and unregulated fishing by Senegalese fishers in the waters of neighbouring countries. This acceptance of reality signifies a level of political maturity that is lacking in many other countries where officialdom prefers to stick its head in the sand.

Daniel also used the opportunity, shortly before leaving Dakar, to hold a press conference with a dozen Senegalese journalists to inform them of a recent study authored by Drs William Cheung, Reg Watson and himself, on global warming and fisheries, which implies a dire future for tropical fisheries. One of the workshop participants suggested to Daniel that the public should be “alerted, but not alarmed” by the trend that this paper describes and the implication for Senegalese fisheries. This point to alert people and not alarm them is an excellent formulation of our job as scientists, and luckily, the Senegalese journalists followed up on it. For those who speak French, you can verify that the Senegalese journalists got the point by reading this article published in Le Soleil Online (www.lesoleil.sn), as an example.

Daniel can also attest that Deng was a big success with the national dress that she was given by the participants (see picture, right)!

References
[1] Gayanilo FC, Sparre P and Pauly D (1996) FAO-ICLARM stock assessment tools (FiSAT). User’s guide. FAO Computerized Information Series No. 8. FAO, Rome. 126 p.
[2] Gayanilo FC and Pauly D (1997) FAO-ICLARM stock assessment tools: reference manual. FAO Computerized Information Series No. 8. FAO, Rome. x+262 p.
[3] Gayanilo FC, Sparre P and Pauly D (2005) FAO-ICLARM stock assessment tools II (FiSAT II). Revised version. User’s guide. FAO Computerized Information Series No. 8. FAO, Rome. vii+168 p.

 

Correction: This is an updated version of the original article, correcting erroneous affiliations.

On using catches to predict abundance

Factions among the fisheries community disagree on whether catch data – the amount of fish drawn from the sea – can be used to assess the health of fish stocks. In a comment piece published in Nature today, the Sea Around Us Project’s Principal Investigator Daniel Pauly shares his views, emphasizing that catch data are often the only type of data we have to tell anything about the status of fisheries.

While developed countries such as the US, Australia and those in Europe are able to use a variety of data, such as size, growth and migration information, as well as survey data, to conduct expert stock assessments, Pauly points out that these come at a cost: anywhere from US$50,000 to millions of dollars per stock. Such costs are not feasible for the majority of developing countries. Furthermore, for 80% of maritime countries, catch is the only data available.

In a second comment piece, Ray Hilborn and Trevor Branch from the School of Aquatic and Fishery Sciences, University of Washington, argue that there are other factors beyond the health of a fish stock that can account for changes in catch. Used on their own, catch data can create confusion and alarm about the abundance of fish stocks, they say.

Pauly agrees that catch data should be used with caution, but adds there is danger in undermining the value of this information. In most countries, the amount of fish caught is the only information available to assess stock health. “If resource-starved governments in developing countries come to think that catch data are of limited use, the world will not see more stock assessments; catch data will just stop being collected,” says Pauly.

The Sea Around Us Project, under the guidance of Pauly, is currently conducting a global evaluation of catch data, from 1950 to present, collated by the Food and Agriculture Organization (FAO) of the United Nations. Results so far reveal that many countries have underreported their catches. The extent of the underreporting is larger in developing countries (about 100-500%; Zeller et al. 2007) than in developed ones (30-50%; Zeller et al. 2011).

To see the full article, please go online to Nature.com: Pauly D (2013) Comment: Does catch reflect abundance? Yes, it is a crucial signal. Nature 494: 303-305.

Zeller D, Booth S, Davis G and Pauly D (2007) Re-estimation of small-scale fisheries catches for U.S. flag island areas in the Western Pacific: The last 50 years. Fishery Bulletin 105: 266-277.

Zeller D, Rossing P, Harper S, Persson L, Booth S and Pauly D (2011) The Baltic Sea: estimates of total fisheries removals 1950-2007. Fisheries Research 108: 356-363.

Colombian Fisheries Bigger Than Reported

colombian_flagA new study published online in Marine Policy last week shows that Colombia, like many other countries around the world, has been underreporting its marine fisheries catches. From 1950–2006, the Colombian catch may have been almost twice the landings reported by FAO on behalf of the country (2.8 times higher in the Atlantic Ocean fisheries; 1.3 times higher in the Pacific Ocean fisheries). Jeffrey Wielgus, a former visiting researcher with the Sea Around Us Project, is lead author of the study and Sea Around Us members Dirk Zeller and Rashid Sumaila are co-authors. The fourth author, Dalila Caicedo-Herrera, is a Colombia-based fisheries researcher. The article is titled: Estimation of fisheries removals and primary economic impact of the small-scale and industrial marine fisheries in Colombia.

Satellite Imagery Can Improve Ocean Data

MaleAtollHow much the oceans are protected?   How much of the globe is covered in coral reefs?  These are important questions that require decent data.  A new study led by Sea Around Us Project member Colette Wabnitz and just released online by the journal Frontiers in Ecology and the Environment reveals that the current data available are too poor for them to be used to evaluate progress toward conservation targets, such as international goals to set aside 20-30% of the oceans as marine protected areas.  Technological advances in satellite imagery, like this image of the North Male atoll in the  Maldives, can help us better determine the true size of coral reefs, mangroves, seagrass, spawning grounds, and other vulnerable marine habitats.  Read the full study here.