2(e) What are the different reproductive values of sea turtles at different life stages? Given those differences, if any, how do programmes to protect eggs and hatchlings compare to programmes that protect large juvenile and adult sea turtles in terms of their likely benefit to the populations and species as a whole?

Dr. S. Eckert:

5.194. The life tables and reproductive value curves of Frazer (1983) and Crouse et. al., (1987) for the loggerhead turtle have clearly demonstrated that large juvenile and adult size classes have the highest reproductive value to the population. These conclusions have recently been supported by Chaloupka and Musick (1996). Crouse utilized these tables and curves to demonstrate in her model that populations of sea turtles will not recover without minimizing the mortality of these size classes, despite rigorous protection of nesting females and their nests. While these models were for loggerheads, there is little reason to suspect that they will be different for other species. In practical conservation terms it must be realized what it means to replace a juvenile turtle. Each juvenile represents 500 or more eggs (based on the survivorship values determined by Frazer (1983) for loggerheads). For most species this represents between 5 and 6 clutches of eggs. Economically, this means that resources equal to the cost of preserving 500 eggs could be invested in the conservation of 1 juvenile turtle.

Dr. J. Frazier:

5.195. "Reproductive value" is an abstraction, not a component of a sea turtle that can be measured directly. It is calculated by taking into account basic characteristics of the life history of the animal, notably rates of mortality, time to maturity, and reproductive contribution. Reproductive value serves as a simple index, which is easier to visualize than a complex of other interacting measures. To calculate the reproductive value, basic information on the life history is needed, and long-term, systematic studies are fundamental for obtaining this kind of information. Up until now only two populations have been adequately studied: loggerhead turtles in the southeast of the United States and loggerhead turtles in Eastern Australia.

5.196. Crouse et. al. (1987) were the first to calculate reproductive values, using detailed, long-term information from loggerheads in the southeast of the United States. They reported:

5.197. Although the details of sea turtle life history differ between species and from population to population, all sea turtles share a relatively common life cycle. Hence, although precise values for the reproductive value will vary, the large difference between reproductive value for eggs and reproductive value for breeders will be a standard feature for all populations. Given this situation, the protection of those life stages which represent the greatest investment for the population takes precedence over those life stages in which rates of mortality are normally rather high, and the reproductive value to the population is low. Nonetheless, every live stage needs to be protected, for the complete removal of any life stage from a population will sooner or later result in its collapse.

Mr. M. Guinea:

5.198. The figures most often quoted indicate that the reproductive value of a nesting female loggerhead is 584 times that of a single loggerhead egg in a Southeastern United States breeding unit (Crouse et. al., 1987). This was the first stage based population dynamics model for any sea turtle species, but other models had been tried for different populations and all have their limitations (Chaloupka and Musick, 1997). Other models are sure to follow. However the general perception is that between 1,000 and 10,000 eggs are required to produce a single nesting female.⁴⁰⁸ There are some assumptions inherent in these models: male to female ratios are 1:1, survivorship is assumed between stages, reproductive longevity is assumed. However, studies of Australian loggerheads place the reproductive values of adult females at between 200 and 400, depending on the population (Heppell et. al., 1996). Reproductive values of each stage of the life cycle appear to differ for each breeding unit.

5.199. All stages of the life cycle require protection. Eggs may have lower reproductive value to larger turtles but all require protection. It depends on the threats to which the breeding unit is exposed. For example, yearly 50 million eggs are deposited on the beaches at Gahirmatha. Using Crouse's figure of 584, this is equal to a recruitment to the nesting population of over 85,000 adult females annually at one generations duration in the future. In view of this figure, an annual mortality of 5,000 from fish trawls and set nets⁴⁰⁹ from a nesting population of 600,000 with a recruitment of 85,000, appears relatively minor.

Mr. H.-C. Liew:

5.200. It is generally believed that out of between 1,000 to 10,000 eggs, only one will survive to adulthood. These figures are, however, estimates as they are not based on scientific evidence but on some models with numerous assumptions. Using such figures, one would be inclined to conclude that the reproductive values of adults are much higher than the young. Similarly in humans, each female can produce 5 - 10 or more children. If one were asked to choose, would it be natural for us to sacrifice all the children leaving only one and save the mother? Knowing also that the child has many more years to go, with many threats before he/she reached adulthood? One should also realize that the probability of survival of humans are much higher as mothers take care of their young. For turtles, there is absolutely no parental care. Many will die, and in fact in nature many do die of natural mortality. Turtles, like may other animals, compensate for this by producing many young. It is thus as important to protect the babies, as much as the mother. Protect the children, they are our future, but we also need mothers and fathers to produce them.

Dr. I. Poiner:

5.201. Crouse et. al., (1987) and Crowder et. al., (1994) used a stage-based-model for United States loggerhead sea turtles to conclude from sensitivity analysis that reducing annual mortality of large juveniles, sub-adults and adults was most important to ensure long-term viability of the stock. This was because of the high relative reproductive value individuals at these stages/ages in the model. Somers (1994) developed a similar stage structured model for an Australian loggerhead stock but concluded that protection of eggs/hatchlings would also have a major impact on long-term stock viability. The reason for the difference was a higher egg/hatchling stage mortality rates used by Somers (Chaloupka and Musick (1997). Chaloupka and Limpus (MS) have developed stochastic simulation model for an Australian loggerhead stock which also suggested that predation on eggs makes a significant contribution to increased mortalities. These different results either reflect the different conditions the United States and Australian sea turtle stocks are exposed to or the limited data on size - and age - specific growth and mortality rates and the lack of data on distribution of stage transition rates.

Question 3: Conservation measures at sea

3(a) Do TEDs, when properly installed and used, significantly reduce the mortality of sea turtles caused by shrimp trawl nets? Do different socio-economic conditions and level of education among fishermen, in particular in developing countries, influence the proper installation and use of TEDs?

Dr. S. Eckert:

5.202. Based on the extensive testing so-called hard TEDs have received in the United States (in contrast to the soft TEDs which have been recently decertified in the United States due to poor performance), there can be no question that TEDs reduce sea turtle mortality when installed and operated properly. (Crouse et. al., 1992., Renaud et. al., 1991, Renaud et. al., 1990, Henwood and Stuntz, 1987, Henwood et. al., 1992, Crowder et. al., 1995). While it is certainly possible to deploy a TED incorrectly, my experience with shrimp fisherman in Georgia indicates that most experienced fisherman understand net deployment methodology very well irrespective of formal education, and thus I would expect that deploying a TED equipped net would pose no particular challenges. While I do not have any direct experience working with trawler fisherman from other countries involved in this dispute, I would not expect them to necessarily be less skilled at operating their own equipment than US fisherman.

Dr. J. Frazier:

5.203. Studies carried out in Australia (Robins-Troeger et. al., 1995), Costa Rica (Arauz, 1997; Arauz et. al., 1997b) and the United States (e.g., Watson and Seidel, 1980; Easley, 1982; Seidel and McVae, 1982; National Research Council, 1990) show that when properly installed and used, different kinds of TEDs can significantly reduce the incidental capture and mortality of sea turtles in shrimp trawl nets. In a recent study, Crowder et. al. (1995) analyzed long-term data from South Carolina and concluded that TEDs "reduce strandings by about 44 per cent relative to the estimated effects of shrimp trawls without TEDs". Furthermore, depending on the design of the TED and conditions of its use, it may successfully exclude more than half the bycatch (e.g., National Research Council, 1990; Robins-Troeger et. al., 1995; Olguin, 1996; Olguin et. al., 1996).

5.204. Under the aegis of the Southeast Asian Fisheries Development Center, trials with the Thai Turtle Free Device (TTFD) (a Thai version of the TED) have been carried out in Malaysia (Ali et. al., 1997), Philippines (Dickson, 1997) and Thailand (Bundit et. al., 1997). The trials in Malaysia showed that a mature hawksbill was successfully excluded (Ali et. al., 1997; SEAFDEC, 1997b). In all three cases the findings indicated that the gear was suitable for use by local fishermen. These results were also reported on by the Southeast Asian Fisheries Development Center, in their newsletter (SEAFDEC, 1996; 1997a; 1997b; 1997c), and results of further tests are awaited. Dr. E. G. Silas, former Director of the Central Marine Fisheries Institute, Cochin, India, proposed the testing of TEDs in Orissa (Silas et. al., 1983a; 1983b), and apparently trials were carried out (Rajagopalan, pers. com.), but further information is not available. A preliminary trial recently carried out in Orissa showed that TEDs installed in local trawls successfully excluded turtles (Department of Fisheries et. al., 1996).

5.205. Fishermen who can successfully use the equipment required to trawl for shrimp will have all the skills needed to properly install and use a TED. As with any new gear, they will require some training and some experience (e.g., Renaud et. al., 1993). Socio-economic distinctions between fishermen are not likely to be relevant to this question. Although in the United States many shrimpers are also boat owners, in developing countries fishermen are routinely employees, working on trawlers owned by investors, for whom fishing is just a business, not a way of life (Mathew, 1990). Level of formal education is not likely to be relevant either, for the skills needed are learned by experience; and certainly in the United States the average level of education for shrimpers is primary school, and a large proportion is illiterate.

Mr. M. Guinea:

5.206. When properly installed and used, a TED will significantly reduce, but not eliminate, the mortality of sea turtles in some shrimp trawls. It would be condescending and culturally insensitive to suggest that any fisherman could not operate a net fitted with a TED. For TEDs to be accepted the technology has to become adapted for the local area. This gives a sense of ownership of the technology and removes the imposition exerted by other countries. Thailand developed two TEDs of which one (Thai Turtle Free Device) is now used on each shrimp trawl net. Australia developed a TED, the AusTED, for use with Australian species of sea turtles on Australian trawl fields (Robins and Campbell, 1997).

Dr. H.-C. Liew:

5.207. Studies conducted by the United States have shown that proper use of TEDs can significantly reduce the mortality of sea turtles caused by shrimp trawl nets. However, even though TED use is mandatory in the United States and in their neighbouring countries, large numbers of turtle stranding still occur there. All shrimp trawlers operating in areas where the likelihood of incidental turtle capture is high should be encouraged to use TEDs or other similar devices. However, proper studies need to be conducted to determine where these areas occur and the seasons involved. Fishermen would not respond positively to the use of TEDs if they hardly catch turtles in their operations. Neither would they use TEDs if they have intentions of eating or selling the turtle.

5.208. After many years of experiments, publicity campaign and TED trials, the United States mandated their use in 1989. Yet, as recent as in 1994, NMFS concluded that poor compliance and enforcement of TED requirements contributed to record numbers of dead sea turtles washed ashore (Crouse, 1996). Considering the socio-economic conditions, educational level, language differences and history of turtle exploitation, it would take at least as long to introduce the use of TEDs, train all the shrimp fishermen, convince them to comply and have effective enforcement. It is important to introduce TED use properly to these fishermen, show how they can benefit from them and getting their full cooperation. To suddenly force them to use TEDs would only be met with blind resistance. Even in the United States where there is mandated use of TEDs, studies are still being conducted to determine if they are needed. NMFS is funding a U$500,000 study conducted by Gary Graham, Texas A&M, Galveston, to determine if TEDs are needed in the offshore waters of the Gulf of Mexico where the "year-long" will place observers on six vessels to see if turtles are caught (Steiner, 1997a).

Dr. I. Poiner:

5.209. Studies of TEDs and other bycatch reduction devices (BRDs) in the United States (Henwood et. al., 1992) and Australia (Brewer et. al., 1995, 1997; Robins-Troeger et. al., 1994) demonstrate that properly installed TEDs are very effective at virtually eliminating the trawl catch of sea-turtles. I am not qualified to comment on the effect of different socio-economic conditions on TED installation and use.

3(b) During the course of this proceeding, it has been stated that TEDs can reduce the number of turtles killed in shrimping activities by 97 per cent or more. This statistic is apparently based on data collected during TEDs testing. Is there any data on TEDs efficiency during commercial shrimping? If so, what does it indicate? Are your aware of data on the rate of turtle stranding in areas where TEDs are currently required or on the relationship between turtle stranding and shrimping activities in areas where TEDs are required?

Dr. S. Eckert:

5.210. Probably the most thorough review of the efficacy of TEDs in the United States is Crouse et. al., (1992) in which they summarize a number of studies on TED use and shrimp catch rates and debunk a large number of anecdotal reports on TED performance. Controlled tests described in Renaud et. al., 1990, 1991 seem to confirm data described in the Crouse et. al., report. (1992). Crowder et. al., (1995) published the most recent and thorough model of the effects TEDs will have on turtle stranding rates and benefits to loggerhead sea turtle populations in South Carolina. Conclusions were that stranding rates should decrease significantly (44 per cent) and that the probability of recovery of this stock (which is currently declining at 5.3 per cent annually) is good.

5.211. Generally three conclusions are put forth in studies on TED effects on commercial fisheries: (i) commercial shrimp catch rates were higher in years after TED's were required (though it is probably not valid to suggest that TED use necessarily resulted in increased catch rates); (ii) shrimp loss ranged from 0.7 - 10 per cent per boat and 0 - 2 per cent for the fleet; however, this value was statistically not significantly different from 0.0 per cent given the sample size and variability in the data; and (iii) performance of TED equipped nets improved with operator experience.

5.212. For other countries, there is one study of TEDs (in this case called Thai Turtle Free Devices (TTFDs)) and shrimping (Senalak and Sujittosakul, 1997); however, the study is probably invalid due to poor data gathering methodology and data analysis. In particular, the data collection seems to rely on dock-side interviews with shrimp boat captains as the sole means of obtaining catch statistics. Such technique is not valid without a means of independent validation of the reported data. Logbook and interview data can often provide important qualitative information, but is usually quantitatively inaccurate. Even more significantly is that the experimental and control groups were fishing in two different years (e.g., non TTFD data was from 1991 and TTFD equipped trawl boat data was from 1992). No attempt was made to correct for between year variation in the data sets. For example, 1991 and 1992 should have been compared to average catch rates over the previous 5 or 10 years to determine if the reported values fall within expected annual variation in catch rates. Without such an analysis it is impossible to know whether the reported differences in catch rates are simply due to annual variation in CPUE or to the use of TTFDs.

5.213. In Malaysia a recent experiment on the use of TEDs in shrimp fisheries concluded that "this study showed that TEDs will prevent marine turtle[s] from being trapped in the net without effecting [sic] the catch of shrimp and fish" (Ali, A. et. al., 1997). Although this study cannot be considered conclusive due to the very small sample size, it does seem to be a well executed and analyzed preliminary experiment.

Dr. J. Frazier:

5.214. The figure of 97 per cent is an arbitrary value which was established by gear specialists from the Pascagoula laboratory of the National Marine Fisheries Service (NMFS), United States. In early tests of TEDs they established a standard for evaluating different designs of TEDs. Because the NMFS design successfully excluded 97 per cent of the turtles that entered the trawl net it was decided that a TED, irrespective of its design, should exclude at least 97 per cent of the turtles in order to be approved by NMFS. This standard was set to provide as much protection as possible for sea turtles, but at the same time allow for a small - and realistic - margin of error. Some of the first experiments on keeping turtles out of shrimp trawls, carried out 20 years, were carried out aboard commercial vessels in Florida, Georgia and South Carolina. Two gear modifications were used, the "reverse barrier trawl" and the "turtle excluder device"; and in both cases they caught significantly less turtles than normal nets (p< 0.001) (Watson and Seidel, 1980; Seidel and McVea, 1982).

5.215. During the last few years there have been clear indications from the commercial shrimp fishery in the United States, that TEDs have significantly reduced turtle mortality. Stranding data from South Carolina for the period 1980 to 1993 show remarkable declines, particularly when TED regulations were in place. Crowder et. al. (1995) concluded that the decline in strandings was because of reduced mortality from TED use. Preliminary analyses of results of a study of "naked net" trawling (i.e., shrimp trawling without TEDs) along the coast of South Carolina in 1997, indicates that the rate of capture of loggerheads (CPUE) is now considerably more than it was when these waters were studied a decade ago by Henwood and Stuntz (1987) (Bransdetter, pers. com.). This increase in turtles, together with the decrease in strandings documented by Crowder et. al. (1995) clearly points to the effect of TEDs in reducing mortality.

5.216. TEDs designed in the United States, and TEDs modified locally have been tested on commercial shrimp trawlers in Australia, Costa Rica, Mexico and Venezuela. Robins et. al. (1997) reported on results of 151 test trawls ("tows") using eight commercial trawlers in north-eastern Australia. They found that the catch of large animals (including turtles) was significantly less in nets with the AusTED both in the subtropical estuarine fishery (p = 0.041) and in the tropical gulf fishery (p<0.01). Arauz et. al. (1997b) reported on the results of 165 test trawls ("drags") using 11 commercial trawlers in Pacific Costa Rica. They found that Super Shooter and Seymour TEDs successfully excluded turtles (as long as bar spacing was not greater than 8 inches): 14 caught in control nets and 2 caught in 1 net with a TED that had been jammed with logs.

5.217. The only country where I know that there is systematic information on turtle strandings is the United States. Increased strandings of Kemp's ridleys, notably in Texas and Louisiana, in 1994 and 1995 (Shaver, 1994; 1995; Steiner, 1994), are thought to be related to improper use of TEDs, use of inadequate TEDs and "intense pulse fishing" (TEWG, 1996:18). As a rule, strandings increase when shrimping activity increases, notably immediately before and immediately after the closure of a shrimping area. This "pulse fishing", very intense trawling in certain coastal areas, results in repeated sweeps of an area over a short period of time which increases the chances that an individual turtle will be captured repeated during a day, undergo successive physiological stress (Lutcavage and Lutz, 1991; Stabenau et. al., 1991), and finally succumb from exhaustion. Pandav et. al., (1997) compiled information on strandings from the Gahirmatha area of Orissa, but the area covered and effort from year to year have varied. TEDs are not used in India. Recently, Guinea and Whiting (1997) have provided evidence of trawl related strandings of four species from the remote coast of Northern Australia, indicating that prawn trawling is a significant source of mortality in these waters. It must be emphasized that the turtles that are found stranded represent only a part - and in certain conditions, only a small part - of all the turtles that have died. Current; tide; tow time; turtle species and size; water depth; water temperature; wind; predator and scavenger densities and behavior; and other factors will affect the way in which turtle carcasses are deposited on the shore. There is no scientifically substantiated conversion factor to convert number of strandings to total number of drown turtles.

5.218. Murphy and Hopkins-Murphy (1989:15) reviewed the results of two experiments that examined the question of what proportion of carcasses are documented as strandings. They reported:

Under the conditions of these two experiments, less than a third of the free-floating carcasses were recovered; hence, mortality will be considerably greater than indicated by just stranding data.

Mr. M. Guinea:

5.219. Data from the Northern Prawn Fishery in Australia indicate: a reduction in small fish bycatch by about 30 per cent, a reduction in large fish, no sea turtles were captured during the trials. Other studies reported a slight increase in prawn catch (4 per cent and 7 per cent) (Mounsey, 1995) which may have been a result of the otter boards spreading wider in response to the reduction in bycatch and therefore in drag at the cod end. The catch was of better quality with fewer broken or damaged shrimp. The better catch of unbroken shrimp could command a higher price.

5.220. Data on turtle stranding are only available from the United States where sea turtles continue to wash ashore even where TEDs are compulsory. Compliance appears to be a problem.⁴¹⁰

Mr. H.-C. Liew:

5.221. Mandatory use of TEDs by commercial shrimpers has been enforced in the United States for the most number of years. Hence, they would provide the best statistics. However, even as recent as in 1997, large numbers of turtle stranding still occur (Coyne, 1997). It even reports that while the 96.9 per cent of the vessels were using TEDs, biologists still see a big decline in dead turtles washing ashore when the Gulf of Mexico is temporarily closed each year to shrimping. In a message by Todd Steiner (1997), he stated that "18 turtles washed up dead in Texas last week, nine had straight-edge cuts at Padre Island National Seashore. Shrimpers were observed by Seashore rangers fishing so close to the beach that it looked like they would run aground. When the shrimper left the area, the strandings ceased." All these examples indicate that problems still exist in the use of TEDs and mandating fishermen to use them does not guarantee that sea turtles will be safe from shrimp trawlers.

Dr. I. Poiner:

5.222. For certification purposes TEDs in the United States need to be at least 97 per cent effective in reducing turtle catches. I am not familiar how this is measured in the certification process. Monitoring of TEDs and other bycatch reduction devices (BRDs) in the United States (Henwood et. al., 1992) and Australia (Brewer et. al., 1995, 1997; Robins-Troeger et. al., 1994) under commercial conditions demonstrate that properly installed TEDs are very effective at virtually eliminating the trawl catch of sea-turtles. Caillouet et. al., (1995) compared the relationship between sea turtle stranding rates and shrimp fishing intensities in the northwestern Gulf of Mexico in 1986-1989 (pre-compulsory compulsory introduction of TEDs) versus 1990-1993 (post introduction of TEDs). They found no difference in stranding rates whereas the expectation was that the introduction of TEDs would reduce the incidental capture of sea turtles and hence diminish or eliminate the statistical relationship between sea turtle stranding rates and shrimp fishing intensities. A variety of hypotheses were suggested to explain the continuation of the statistical relationship, including violation of TED regulations in the fisheries.

3(c) In your view, is the obligatory use of TEDs for shrimp trawling an essential conservation measure in all areas where sea turtles occur? Or can alternative measures such as seasonal and time closures, areas closures or tow-time limitations achieve equivalent or better results?

Dr. S. Eckert:

5.223. It is my belief that TEDs provide the best opportunity to reduce turtle bycatch with the greatest efficiency and lowest cost to the fishing industry. Further, as I noted above, I believe it is the most easily enforced conservation measure available. The problem with seasonal and time closures are that: (i) enforcement requires extensive and continual law enforcement presence on the water in the closed area. With the costs of operating enforcement vessels and the extensive areas fished, this is generally beyond the capacity of most countries (including the United States) to support; (ii) such closures do not facilitate rapid adjustment for stochastic fluctuations in the migratory patterns of turtles; and (iii) tow time limitations are almost impossible to enforce and actually do not provide much protection to turtles subject to multiple captures (Stabenau, 1991).

Dr. J. Frazier:

5.224. Nationals from three of the countries involved have expressed the need to employ, or at least test and seriously consider TEDs in their fisheries: India (e.g., Silas et. al., 1983a; 1983b; James et. al., 1989; Department of Fisheries et. al., 1996; Mohanty-Hejmadi, 1996; Sarkar et. al., 1996; Behera, 1997c; Pandav et. al., 1997); Malaysia (e.g., Suliansa et. al., 1996); and United States (e.g., National Research Council, 1990; Weber et. al., 1995). In addition, tests carried out in four of these countries have indicated that TEDs are suitable for local use: India (e.g., Department of Fisheries et. al., 1996); Malaysia (Ali et. al., 1997); Thailand (Bundit et. al., 1997); and United States (e.g., National Research Council, 1990; Weber et. al., 1995).

5.225. As a stop-gap measure, the use of TEDs in all shrimp trawlers should slow the rate of destruction of marine resources, including sea turtles. The real problem, however, is much, much deeper and involves the environmental and social effects of bottom trawling and bycatch destruction as carried out by modern fisheries. In my view, there is ample evidence for banning trawling from countries with dense human populations, high dependency on fish for food, and where modern fisheries (e.g., the tropical shrimp fishery) are focused on exporting food to industrialized nations while local citizens of these exporting countries find it more and more difficult to find adequate food for themselves and their families. Certainly, people from many different fishing communities around the world have called for a ban on trawling (O'Riordan, 1994; SAMUDRA, 1994), and ample evidence in the fisheries literature shows without a doubt that modern fisheries are overcapitalized, grossly destructive of the environment, and supporting greater social polarization and degradation on national, regional and international levels.

5.226. Area closures do not work because of a lack of enforcement. This has been widely documented in many countries, including those involved in this dispute (e.g., Mathew, 1990; Yamamoto, 1994; Pauly, 1995; Behera, 1997a; Pandav et. al., 1997). Area closures, designed to minimize bycatch of protected species, may actually create problems, for the effect may be simply to displace fishing effort to other areas. To accomplish the goals of the closure, it may be necessary to close a much larger area than originally contemplated, or even to stop fishing (Murawski, 1995:8). The logic behind seasonal and time closures is to remove fishing effort from a particular species, during a critical period. However, the shrimp trawl industry is heavily overcapitalized, and shrimp stocks are generally in decline, so there is intense competition to fish and catch shrimps. Hence, even if enforcement were possible, the usual result of temporal closures is to concentrate fishing effort just before and just after the closure ("pulse fishing"). In general, seasonal and time closures simply offset mortality around the time of the closure.

5.227. Tow-time (the period of time that the trawl net is in the water) limitations are least enforceable of all measures. Furthermore, recent information indicates that forced submergences of more than 30 minutes may be fatal to many sea turtles (Lutcavage and Lutz, 1991; Stabenau et. al., 1991), so to be effective, maximum tow-times would have to be 30 minutes, not 60 as has been frequently claimed. Even 60 minute two times are inconvenient and uneconomical for most trawlers, so there is little chance that they would abide by 30 minute tow-times.

5.228. It must be pointed out that in a well managed fishery, with controlled fleet size and closed entry, such as found in Australia, it has been possible to work with the fishermen and enlist their collaboration (Kennelly and Broadhurst, 1995; Tucker et. al., 1997). However, this is very much the exception, and not anything like the case for any of the countries involved in this dispute where the fishery is open entry and basically a free-for-all.

Mr. M. Guinea:

5.229. "TEDs are not an ultimate solution, they should only be seen as part of an integrated approach to sea turtle conservation and restoration." (Steiner, 1993, p. 180). I agree with the above quote by Todd Steiner in that TEDs are just one option in the array of management options open to the managers of shrimp fisheries. Any of the options mentioned previously in my submission could be employed with or without TEDs. The management options should be tailored to the Fishery. Recent population models have shown that when TEDs are used in conjunction with egg protection, the population has a greater chance of survival than if either egg protection or TEDs were used individually (Grand and Beissinger, 1997).

Mr. H.-C. Liew:

5.230. In certain areas, TED use is essential, but scientific studies must be conducted with unbiased data to show its necessity and to convince the fishermen in those areas why they should used them. TED use should not be mandated blindly without proper studies. When the Gulf of Mexico is temporarily closed each year to shrimping, biologists in the United States found a significant decline in dead turtle strandings compared to shrimpers using TEDs even with a 96.9 per cent compliance by the fishing vessels.

Dr. I. Poiner:

5.231. The obligatory use of TEDs to reduce the incidental mortality of sea turtles in shrimp trawls is one management tool that can be used but there are others, including area, seasonal and time closures and tow-time limitations that either individually or together may achieve the same reductions in catch. Which suite of management tools to be used will depend on management objectives, the nature of the fishery and ease of surveillance and enforcement. Tucker et. al., (1997) compared the Australian and United States approaches to the introduction of TEDs to reduce turtle mortalities. They suggest a participatory (non legislative) solution to trawl bycatch issues via negotiation and mediation between stakeholders has substantial advantages in the Australian situation (nature of the fisheries, nature of the people, political system, etc.) over a litigation and legislation approach as was/is use in the United States.

To Continue With Chapter 5.232

⁴⁰⁸ See above paragraph 3.19.

⁴⁰⁹ See above paragraphs 3.49, 3.51, 3.59 and 3.77.

⁴¹⁰ See above paragraphs 3.51, 3.83 and 3.84.