EVALUATING THE SURVIVORSHIP OF ELASMOBRANCHS CAPTURED BY BOTTOM TRAWLERS: A Pilot Plan for Conservation of Sharks, Skates and Rays. RUFFORD SMALL GRANT (for Nature Conservation) In association with the Whitley Laing Foundation Project Team Project leader: Team members: Gustavo E. Chiaramonte Jorge E. Perez Matías Sidders Matías Urcola Leandro L. Tamini. Contact Lic. Gustavo E. Chiaramonte División Ictiología – Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” Av. Angel Gallardo 470 (C1405DJR). Ciudad Autónoma de Buenos Aires, Argentina. Phone number: 54-11-4982-9410 (# 219) Fax number: 54-11-4982-5243. E-mail: gchiaram@mail.retina.ar TABLE OF CONTENTS Table of Contents ____________________________________________________________ 3 Introduction ________________________________________________________________ 4 Changes in fish community structure___________________________________________________ 8 Chondrichthyan fisheries in Argentina _________________________________________________ 9 Buenos Aires province coastal waters skate community ___________________________________ 11 Project Aims and Objectives__________________________________________________ 11 Project Implementation______________________________________________________ 13 Methodology of the scientific activities________________________________________________ 13 Results _________________________________________________________________________ 16 Educational Plan ___________________________________________________________ 18 Education goals __________________________________________________________________ 18 Targets of the educational work______________________________________________________ 18 Workshop for teachers, community leaders and fishermen _________________________________ 19 Didactic material and panellists ______________________________________________________ 20 Programme and activities___________________________________________________________ 21 Other Outputs _____________________________________________________________ 24 Highlights & Conservation Problems __________________________________________ 25 Recommendations __________________________________________________________ 25 References_________________________________________________________________ 26 INTRODUCTION Chondrichthyans are a common but unspecified by-catch in many fisheries worldwide, particularly those using bottom trawls. In most countries, there are no regulations over the amount taken. Unfortunately, little skate species-specific data are available from areas with the highest catches, and virtually nothing is known about the status of individual stocks. However, large annual or rapidly increasing landings in recent times are cause of concern. In view of the high endemism (possibly up to 55% of 230 known species), skates currently represent one of the most threatened groups of all marine species. However, assessing their vulnerability is difficult due to the practice of aggregating catch statistics. Concerns over the impact of fishing on shark and batoid populations around the world are currently being raised at an international level through a number of fora. The Species Survival Commission of IUCN has formed the Shark Specialist Group (SSG), which is working on a global Action Plan for the conservation and management of sharks. The parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) took unprecedented action in 1994 by mandating a review of the status and trade in sharks, a group of animals not currently listed on the CITES Appendices. As part of the process of CITES consults, the United Nations Food and Agriculture Organization (FAO) began a work with the topic and set up a Technical Working Group (TWG) on sharks. Concerns rising about chondrichthyans involve several factors. Sharks and batoids appear to be particularly vulnerable to over exploitation because of their K-selected life-history strategy –characterized by slow growth, late attainment of sexual maturity, long life spans, low fecundity, and natural mortality, and a close relationship between the number of young produced and the size of the breeding biomass–. The poor record of sustainability of fisheries targeted shark species is cited as evidence of their vulnerability, but is also magnified by the fact that few countries have tools of management for these resources. Poor baseline data on species identification and landings have been collected because sharks have historically been of low economical value in most countries, and lack of data is crucial in the concerns. As many of the landings of sharks becomes from fisheries targeting other species or from multispecies fisheries, or are in countries without adequate fisheries information-gathering systems, much of the catch goes unrecorded. Compounding the problem is the oceanic and highly migratory nature of many species, placing them outside the responsibility of individual countries and outside the mandate of international bodies. These factors have contributed to a situation where the reported chondrichthyan catch is only about half of the estimated global catch (Bonfil, 1994). There is ample historic evidence of major declines in chondrichthyan populations from fisheries around the world. Global reported landings of chondrichthyan fishes have been increasing steadily since 1984 and in 1996 stand about 760,000 t (Stevens et al., 2000). However, the total catch is probably nearer to 1.5 million tones, due to a large unreported by-catch (Bonfil, 1994). During the 1940’s, several target shark fisheries developed in response to the market for vitamin A from livers; more recently, fisheries have targeted chondrichthyan for their meat, fins, livers, and other products. The literature contains many references to the apparent “boom and bust” pattern of this fisheries during the 1940–1970 period (Holden, 1974; Anderson, 1990; Compagno, 1990). In most cases, economic and marketing factors were involved in the collapse and it is difficult to disentangle these from biological factors. Where the species has a more restricted range and where the fishery was intensive and expanded rapidly, stock collapse become more plausible. Over the last 20 years, a serious decline has been documented for a number of batoid species. The common skate (Dipturus batis) has been “brought to the brink of extinction” by trawling in the Irish Sea (Brander, 1981) and the barndoor skate (D. laevis) could become the first well-documented example of extinction in a marine fish species if current trends continue (Casey & Myers, 1998). Roberts & Hawkins (1999) addressed the issue of marine extinctions. Only one species, the barndoor skate (Casey & Myers, 1998), is known to have been driven to the verge of extinction due to large scale fisheries operations. Three other skates are considered locally extinct, the common skate, the long nose skate (Dipturus oxyrhinchus), and the white skate (Rostroraja alba) (Brander, 1981; Dulvy et al., 2000). Hoenig & Gruber (1990) suggested the possibility of ranking species according to their resilience based on critical aspects of their life history. They considered that natural mortality rate, age at maturity, fecundity, and, in particular, the intrinsic rate of population increase might be useful for this purpose. Brander (1981) and Walker & Hislop (1998) demonstrated that changes in fecundity have a relatively small effect on the mortality at which the Irish Sea stock of the common skate and North Sea populations of rajoids collapse. Rather, it is the net recruitment rate that is important, and juvenile survival appears to be the key factor. Brander (1981) concluded that increased survival of juveniles provides grater resilience to fishing pressure than increased fecundity. In reality species may show a combination of different compensatory changes. Pratt & Casey (1990) reviewed reproductive and growth parameters that might be used to indicate vulnerability of chondrichthyans species to fisheries, while Smith et al. (1998) ranked 26 species according to their intrinsic rate of population increase, providing a relative measure of their recovery ability from exploitation (‘rebound’ potential). Brander (1981) ranked various skate species according to the total mortality that their populations could withstand without collapsing, based on age at maturity and fecundity. Walker & Hislop (1998) produced a similar ranking using demographic models that estimated levels of total mortality below which the populations decline. The larger, late maturing species, such as D. batis, tended to be the least productive among the skates species examined. Demographic parameters such as rebound potential may be the most useful for ranking species for management or conservation prioritization. However, there are significant problems in obtaining suitable data to allow consistent calculation of the different parameters required for large numbers of species (Smith et al., 1998). Most life history trait variation, including growth, age at maturity, offspring size, and fecundity, is correlated with body size (Holden, 1973; Brander, 1981; Casey & Myers, 1998). As a result, body size is correlated to demography (Walker & Hislop, 1998; Dulvy et al., 2000). In the North Sea, the four largest species have undergone declines, while the two smallest species have increased in abundance (Walker & Heessen, 1996; Rijnsdorp et al., 1996; Walker & Hislop, 1998). In the Irish Sea, there is evidence for localized extirpation of the three largest species over the past century. Of the remaining five species, the two largest ones are declining in abundance, whereas the two smallest species have increased in abundance (Brander, 1981; Dulvy et al., 2000). Although the largest species, the barndoor skate, has been nearly extirpated in the northern part of its range and is at very low abundance in the southerly part of its range (Casey and Myers, 1998), the next largest species, the winter skate (Leucoraja ocellata), is increasing in abundance and some smaller skates are decreasing in abundance. However, such a pattern is less clear for the skates of Southwestern Atlantic. Changes in fish community structure Most elasmobranches are predators at, or near, the top of marine food chains. How does their removal affect the structure and function of marine ecosystems? The direct effects of fishing through the capture of individual species can result in changes in abundance, size structure, life history parameters (density-dependent change), and at the extreme, could lead to extinction. The indirect effect involves trophic interactions at the community level through selective removal of predator or prey species, removal of competitors, species replacement, and enhancement of food supply through discards. Large scale exploitation has led to changes in fish community structure. A decrease in abundance, particularly of the larger size classes, is a common feature of exploited fish populations (Russ, 1991). Fishers tend to remove the largest species first and then way down the food chain catching smaller species (Pauly et al., 1998). Small species may also be less desirable on the market, and may therefore be subjected to lower fishing mortality (Jennings & Kaiser, 1998; Jennings et al., 1999b). Species replacement over a period of about a decade has been reported on Georges Bank (Murawaski & Idoine, 1992), while in the other areas such a pattern is either not evident (North Sea; Pope et al., 1988) or not consistent over several years (Scotian shelf; Duplisea et al., 1997). Skates tend to be generalist bottom feeders and there is considerable dietary overlap between species. Dulvy et al. (2000) suggest that the removal of larger skates may have led an increase in smaller skates through increased food availability. This competitive release has also been suggested as the reason for the increase of A. radiata in the North Sea (Walker & Heesen, 1996). Jennings & Kaiser (1998) conclude that intraspecies competition and predation has rarely been shown to control cycles in fish populations and those there little convincing evidences to suggest that fishing has caused compensatory replacement of one fish stock for another. Daan (1980) also concluded that clear cases of species replacement due to fishing were hard to find. The assumption of replacement of species supposes that skates and rays share their food niche. Chondrichthyan fisheries in Argentina Among the first biologic researches on sharks made in Argentina (Berg, 1895; Lahille, 1921a, 1921b and 1928; Marini, 1929 and 1930; Pozzi & Bordalé, 1935; Marini, 1936; López, 1947), only Siccardi (1950) considered the fishing problem when she published the oldest statistical data on commercial exploitation of sharks, dating from 1935. To this pioneer work should be added the one by Angelescu (unpublished, c. 1954), in which the functioning of a small coastal shark fishery in Monte Hermoso is described (Fig. 1), on the base of the tope or school shark, Galeorhinus galeus. Partly because of zoogeographic factors, and also because of reasons of human history and demography, the traditional fisheries in Argentina were in the southcenter of the Buenos Aires province and north of Patagonia. From South to North, the main fishing ports towards the middle of the ‘50 were Rawson, Patagones, Puerto Quequén and Mar del Plata (Fig. 1). Figure 1. South West Atlantic Ocean from Uruguay to North Patagonia. Principal fishing ports for sharks are indicated. Although the statistics of landings of Chondrichthyans began to be taken in Argentina towards the end of the ’20 of the XX century, it was only during World War II that shark fishing became perceptible. In Figure 2, data of 70 years of chondrichthyan landings in Argentina are shown. The first impulse for shark fishing about the beginning of the ‘40 of the XX century was due to the need to replace the codfish and stockfish, which up to that time had been imported, mainly from Norway (Siccardi, 1950). Shark flesh was salted down, but the "codfish" ("bacalao") thus obtained was not of good quality, since not enough drying time was allowed, due to imperious need of replacing the imported produce. Besides, salt of national origin was of poor quality. 35 Figure 2. Declared landings of Chondrichthyes in Argentina. Period 1934–2005. 30 Siccardi (1950) adds that 25 there was an unsuccessful 20 attempt to use the calcine 15 gristle 10 manufacture of buttons. MT x 1000 40 5 Afterwards, for in the 1943, 0 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Year production of liver oil began; this was obtained mainly from "cazón", G. galeus. In the same year, according to the author, 45 factories appeared as registered for the elaboration of this produce in the Ministerio de Agricultura de la Nación (National Ministry for Agriculture). The first country to which liver oil was exported was U.S.A.; afterwards, there were sales to UK, Italy, Sweden, Switzerland, France, and some Latin-American countries. It was only towards the end of the ‘80s of the XX century that the problem of shark fishing was again considered (Corcuera & Chiaramonte, 1992); the first detailed information on functioning and calculations of Catch per Unit Effort (CPUE) for a shark fishery in Argentina was then obtained, as well as an estimation of the economic importance of the fisheries. It is known that in argentine waters are found about 35 species of sharks (Menni, 1986), 34 of batoids (Argentina–Uruguay waters, Pequeño & Lamilla, 1993), and a single one of Holocephali; however, only three species of shark are object of directed fishing: the smooth hound, Mustelus schmitti, the tope shark or soup fin shark, G. galeus and the copper shark, Carcharhinus brachyurus. Other species of chondrichthyans with commercial importance as bycatch are the angel sharks, Squatina spp., the sand tiger shark, Carcharias taurus, the cockfish, Callorhinchus callorhynchus, and the batoids, with several species. Buenos Aires province coastal waters skate community It is no clear if the process of replacement is occurring in the coastal waters of the Buenos Aires Province, Argentina, because fishing pressure includes small no commercial species of skates that compound the most important group discarded (Tamini et al., 2006). From 1996 until today the commercial fishery of skates had raised a similar level of capture which carried on the commercial skates of the North Sea and North Atlantic to extinction. In Argentine waters, many of the landings of elasmobranches are from fisheries targeting other species. In addition, the official statistic of catches lumps species into categories such as “skates and rays”. In these conditions any plan of conservation and management becomes impossible. PROJECT AIMS AND OBJECTIVES The exploitation of elasmobranchs in Argentina reached the same levels that conducted some species to the extinction in other fisheries around the world. Although some species show strong evidences of declines (school shark, sandtiger shark, copper shark, and some species of skates), few and soft actions were adopted by the national fisheries authorities in order to prevent the same catastrophes in Argentine seas. Even so, the mortality of elasmobranchs in bottom trawl gear is species-specific and it has not been estimated until today. So, differences in the survivorship were not evaluated in a conservation approach. In the Puerto Quequén coastal bottom trawl fishery at least 23 chondrichthyan species were identified, from which 14 are commercial species (Tamini, 2001). Differences in survivorship of the commercial species could be use as a management tool to mitigate the fish mortality by bottom trawlers. Since mature males and females specimens of elasmobranch are easy to recognize, species with medium to high survivorship could be protected by a ban for reproductive females. This ban needs some other tools to be successful (e.g. an educational plan for the fishery community). This conservation tool helps to stop the depletion of the species of elasmobranchs threatened by the over-fishing, sets a seed for the development of a conservation plan for elasmobranchs in Argentina and works in order to transform coastal fisheries into a sustainable activity for the conservation of both fish and fishers. Surveys onboard the commercial coastal fleet at Puerto Quequén, allow us to estimate the figures of fatalities and survivors in elasmobranchs captured by the bottom trawlers. In the case of survivors we estimate the real chances of the fishes to survive. Based in this result we make a management recommendation to the national and local authorities to mitigate the fishing mortality of the reproductive specimens. PROJECT IMPLEMENTATION Methodology of the scientific activities Onboard work The scientific activities were conducted onboard the Puerto Quequén (Fig. 1) bottom trawlers F/V “Punta Mogotes” and F/V “Volador”. Each fish trip lasted 48–108 hours, and during this time period a total of 12–24 tows were made. The tows were ~2 hours long and conducted at a towing speed of 2–3 knots over the ground in waters 35–55 meters depth. Data were collected seasonally by on board observers during 6 trips (75 tows) between November 2004 and February 2006 and samples of capture were obtained in only 47 tows. Random sampling was not attempted. We decided to work with all available hauls, since observers had no option to choose in which commercial vessel or trip to work on, as well as which haul to sample on. The data of each tow were registered (date, latitude, longitude, tow speed and depth). Onboard work comprised two phases or different kinds of activities: a) one observational and b) other experimental. Figure 3. The crew opens the footrope of the net and the catch is released on the deck. a) The observational phase comprises the identification of each species of elasmobranch from each haul. We registered the time spent between the opening of the footrope of the net onboard by the crew (and the release of the catch on the deck; Fig. 3) and the selection process of the capture by the crew (commercial and discard specimens) which invariably involved the crew walking among and over many fish (Fig. 4). Figure 4. Jorge Pérez observes the selection process of the capture by the crew (commercial and discard specimens). During this process the identities and numbers species of the were Simultaneously, the chondrichthyan recorded. fishes were assigned according to three major categories (Conditions) of the stamina index (modified from Laptikhovsky, 2004; Fig. 5). The same categories were applied in the start of each experiment in the experimental phase. Figure 5. The observational process of assign the stamina index to each fish. The modified categories are: Condition 1– Alive, flapping wings or with lateral and strong movements of the body. Condition 2– Immobile, but alive, move their spiracles or gill slits regularly and reacting to irritation. Condition 3– Dead. Paralyzed, body stiffened. Figure 6. Tanks were secured inside the forward deck. At the same time, other observer randomly removed some specimen of each species in order to lay it into two tanks, which were secured inside the forward deck and were supplied with a constant flow of fresh seawater (Fig. 6). b) These fishes were part of the second “experimental” phase. In this phase, each specimen was observed once each 10 minute during the first half hour, and then once each 30 minutes until 2–5 hours since the beginning of the experiment. In each observation until the fish was released to the sea or returned to the crew, one category of the stamina index was assigned. After this, each specimen was sexed and the body length or disc width was measured to the nearest centimetre (Fig. 7). Figure 7. A female of Psammobatis bergi during the process of measure. Results A total of 1,768 specimens of elasmobranch fishes were identified during the study. These fishes were classified into 10 families, 18 known species and one new species 1 (Table 1). The three most common species which comprises the 80% of the sample were Sympterygia bonapartii, Rioraja agassizi and Squatina punctata. Table 1. Status, number, and percentage number of species in the catch from 47 commercial bottom trawls off Puerto Quequén. TAXON STATUS COMMON NAME NUMBER % NUMBER BATOIDS Arhynchobatidae Atlantoraja castelnaui C painted skate 61 3.45 Atlantoraja cyclophora C circle skate 114 6.45 Psammobatis bergi B sand skate 14 0.79 Psammobatis extenta B sand skate 4 0.23 Rioraja agassizi C smooth skate 366 20.70 Sympterygia acuta C acute skate 55 3.11 Sympterygia bonapartii C marble skate 772 43.67 Myliobatidae Myliobatis goodei B eagle ray 4 0.20 Rajidae Dipturus chilensis C bignose skate 10 0.60 Rhinobatidae Zapteryx brevirostris B guitarfish 9 0.50 Torpedinidae Discopyge tschudii B electric ray 19 1.10 Sp. nov. B electric ray 2 0.10 SHARKS Lamnidae Carcharias taurus C sandbar shark 1 0.05 Hexanchidae Notorynchus cepedianus C spotted sevengill shark 1 0.05 Squalidae Squalus acanthias B spinny dogfish 1 0.05 Squatinidae Squatina occulta C angelshark 1 0.05 Squatina punctata C angelshark 277 15.70 Triakidae Galeorhinus galeus C tope shark 5 0.30 Mustelus schmitti C narrownose smoothound 52 2.95 The frequencies of the stamina index of the specimens for the most frequent species in the samples were plotted (Fig. 8). This figure allows us to determine that five of the eleven species examined appear to be in trouble: more than 50% of the The new taxon will be described by Dr. Roberto Menni and Dr. Mirta García from La Plata Museum. 1 specimens were in not a good condition when they were released on deck (Atlantoraja castelnaui, Mustelus schmitti, Psammobatis bergi, Sympterygia acuta and Zapteryx brevirostris). . Condition 1 Condition 2 Condition 3 100.0 90.0 The second or so called “experimental” phase (Fig. 9a 60.0 & 9b) involves twelve species 50.0 with a total of 95 specimens 40.0 observed. Eight of these 30.0 species exhibit a percentage of 20.0 survival rates above 50% 10.0 (Table 2). The skate Atlantoraja 0.0 cyclophora showed the worst survival rate whilst the electric ray Dicopyge tschudii and the angelshark Squatina punctata exhibit the best performance (Table 2). 80.0 br ev ir o st ris Z. pu nc ta ta S. S. bo na pa rti i S. ac ut a be rg i ag as siz i R. P. i .s ch m i tt M sc hu di i D .t D .c hi len sis A. ca ste l na ui A .c yc lo ph or a 70.0 % Figure 8. The stamina index assigned to each species according to three major categories (Condition 1, Condition 2 and Condition 3; see the section Methodology of the scientific activities). Figure 9a & 9b. On the right, the student Matías Urcola examined some specimens of electric rays during the experimental phase onboard the F/V Punta Mogotes in order to assign the stamina index according to three major categories (Condition 1, Condition 2 and Condition 3; see the section Methodology of the scientific activities). Below, Jorge Perez supplied with fresh seawater the bins during other sailing onboard the same ship. Table 2. Status, number, and percentage number of species in the sample of the experimental phase from 47 hauls of commercial bottom trawls off Puerto Quequén. Atlantoraja castelnaui Atlantoraja cyclophora Dicopyge tschudii Galeorhinus galeus Mustelus schmitti Psammobatis bergi Psammobatis extenta Rioraja agassizi Squatina punctata Sympterygia acuta Sympterygia bonapartii Zapteryx brevirostris Total n TL (mm) 8 7 7 2 2 4 1 20 5 5 26 8 95 520-735 350-610 285-460 800-820 420-540 450-475 300 400-660 250-660 520-630 400-760 495-630 Time spent in fish bin (min) 15-210 30-210 15-30 60-210 15-30 15-30 30 15-180 15-30 15-270 15-120 15-30 Survival rate (%) 88 29 100 50 0 75 0 60 100 60 88 100 EDUCATIONAL PLAN Education goals • To generate local and regional consciousness about the peril of chondrichtyan fishes at the argentine coast, and the requirements for the conservation of the • species. To provide local teachers, through educational activities, information and tools that allow them to improve their work with the local pupils. Targets of the educational work Environmental education activities were addressed to Necochea and neighboring community members, more specifically to fishermen, educators and community leaders. Three different kinds of audience will be distinguished in order to make the educational activity: • Community leaders: to bring up local leaders that will be able to continue with the educational activities about the environmental in a long term. • Teachers and indirectly girls and boys, who attend schools of the project area: to work on subjects about environmental care, address specials emphasis in • topics related with this project. Fishermen: to develop and work with topics referred to the suitable use of fishing gears that are used in order to decrease the impact on elasmobranch populations. Workshop for teachers, community leaders and fishermen On March 2005, we made a trip to Necochea to present the educational team to different actors of the community. Our objective was to make a diagnostic evaluation to detect their appreciation about the local coastal commercial fishery and the impact on the marine ecosystem and to begin to design of the educative plan for activities with teachers, community leaders and fishermen. To accomplish this, we organized several meetings and interviews with the above mentioned actors, and we analyzed with them the opportunity of developing activities together. Some people we met were: • Lic. Marcela Mastrocola, Pro Secretaria General of the Unidad de Enseñanza Universitaria Quequén, Universidad Nacional del Centro de la Provincia de • • Buenos Aires. Eduardo Catalisano, school teacher at Puerto Quequén. Luis Nogueira, Technician of the CONICET (Consejo de Investigaciones Científicas y Técnicas), who works at the Estación Hidrobiológica de Puerto Quequén (which belongs to the Museo Argentino de Ciencias Naturales • • “Bernardino Rivadavia”). Ernesto Klocker head of the Prefectura Naval Argentina–Puerto Quequén (PNA is the police for the Marine and Freshwater matters). The skippers and crew of the F/V Punta Mogotes, F/V Volador, F/V Neptunia and F/V Virgen de las Nieves. As a result of the interviews, we decided to develop a Workshop called “Pesca costera: ¿qué, cómo y cuánto se pesca?” (Coastal fishery: what, how and how many is fished?). We also distinguished the major themes to include in the educative program: • • • • • • • Sort of fisheries Fishing gears Invertebrates, Chondrichthyes, Bonefishes, Turtles, Seabirds, Marine mammals and their relationship with the fishery Incidental captures Overfishing, bycatch and mitigation tools The argentine framework for fisheries and the process from the ship to the market of the fish products The Puerto Quequén coastal fishery, and the life strategies of the fishermen in the locality Didactic material and panellists We produce specific material which summarizes the main contents deals during the workshop, in order to facilitate the comprehension during it and to provide material for further consults. Each participant was provided with this material (minimal contents in a hard copy and a more complete CD–ROM) for further searches. The persons who contribute to the workshop were: • Chiaramonte, Gustavo E. (biologist; head of this RSG Project; workshop coordinator) • González Carman, Victoria (undergraduate biologist; member of Regional Program of Research and Conservation of Marine Turtles of Argentina) • Iwaszkiw, Juan (biologist; former Director for Fisheries of Buenos Aires province) • Nogueira, José Luis (technician; Estación Hidrobiológica de Puerto Quequén) • Pastorino, Guido (biologist; Academic Secretariat of the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”) • Perez, Jorge E. (biologist; team member) • Prosdocimi, Laura (biologist; member of Regional Program of Research and Conservation of Marine Turtles of Argentina) • Retta, Susana (biologist. Doctorate student at Mar del Plata Univ.; Fig. 10) • Rispoli, Florencia (anthropologist; doctorate student at Mar del Plata University) • Tamini, Leandro Luis (biologist; team member; workshop coordinator) Figure 10. The ichthyologist Susana Retta illustrates about the bonefishes captured by the Puerto Quequén coastal fleet. Programme and activities The workshop was developing during the evening of May 17, 18 and 19 at the Unidad de Enseñanza Universitaria Quequén, Universidad Nacional del Centro de la Provincia de Buenos Aires with a total of 25 attendants. These activities lasted 12 hours. Below is summarized the detailed programme: 1st Day: Unit 1: Unit 2: Unit 3: Unit 4: 2nd Day: Unit 5: Unit 6: Unit 7: Unit 8: 3rd Day: Unit 9: Unit 10: Unit 11: Sort of fisheries (Gustavo–Leandro; Fig. 11) Fishing gears (Jorge–Gustavo–Leandro) Invertebrates (Guido) Invertebrates (Guido) Cartilaginous fishes – Target species (Gustavo) Bonefishes (Susana) Marine turtles – Incidental captures (Victoria–Laura) Seabirds – incidental captures (Leandro) Marine mammals – incidental captures (Jorge) From the ship to the market (Juan; Fig. 12) The argentine framework for fisheries (Juan) Coastal fleet operation in Puerto Quequén (Luis) Unit 12: Life strategies of the fishermen home’s (Florencia) Overfishing, bycatch and mitigation tools (Gustavo-LeandroJorge) Figure 11. I discuss with one attendant about the trawlers of the Puerto Quequén coastal fleet. The workshop addressed to was three different kinds of public: institutional and business representatives, teachers and fishermen. This composition of the audience allowed us to exchange their experiences and knowledge with us and to enrich our work. Figure 12. Juan explains the needs of the fish meet in order to commercialize it. The workshop received public diffusion through the local newspaper EcosDiarios, which summarised the activity in the Sunday edition of May 21st (Fig. 13). Figure 13. Media article with the results of the workshop . Other Outputs We exhibit this poster at the Society for the Conservation Biology meeting (San Jose, California; 24–28 June 2006). HIGHLIGHTS & CONSERVATION PROBLEMS We assessed two sources of concerns about the survivorship chances of sharks, skates and rays: a. the condition of the fish when they are released on the deck b. the fish rate of recovery We could state that each source of concerns is species dependant. The angel sharks and electric rays showed good stamina index on deck and also good rate of recovery. The commercial species of skates exhibit middle to good rate of recovery (with the exception of A. cyclophora), whilst the shark M. schmitti exhibit a bad performance in both stages of the assessment. We also identified two other variables (a] the time of trawling; b] the time spent by skates on deck before they are released to the sea) that could influence the survival rate of the elasmobranches. These variables will be tested in deeper during the process of writing the scientific paper during the next months. RECOMMENDATIONS The fieldwork of the project onboard the ships and our previous knowledge allow us to realize that only three ways of action should be recommended: a. the urgent need of apply the International Plan of Action for the Management of Fishing Capacity, in order to diminish the coastal fishing pressure over the elasmobranch species b. the implementation of a program with the crews of coastal fleet to encourage them to cooperate with the conservation of the species, recognizing the threatened species c. the implementation of a program with the crews of coastal fleet in order to release the individuals of threatened species to the sea according with our results of the Stamina Index Since the coastal fishery is a multispecies fishery, and at least 19 species of elasmobranches occur, other management tools such as ban for species or group of species, as well as the implementation of closure areas, are not recommendable. REFERENCES Anderson, E.D. 1990. 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