14. NATIONAL REPORT ON THE SPINY LOBSTER FISHERY OF THE TURKS AND CAICOS ISLANDS

Wesley Clerveaux^[32], Rafael Puga and Paul Medley

Description of Fishery

The Turks and Caicos Islands (TCI) are a group of calcareous islands located at the southern end of the Bahamian archipelago in the Atlantic Ocean bisected by three shallow water banks: Caicos Bank, Turks Bank and Mouchoir Bank.

Industrial fishing for the spiny lobster (Panulirus argus) is based on the Caicos Bank the largest of the three areas of shallow water banks, with an area of approximately 6 500 km². A small number of vessels periodically engage in subsistence level artisanal fishing in the Turks Bank, whereas the Mouchoir Bank is neglected because of its proximity to landing sites.

Economically, the spiny lobster fishery is the most important marine resource in the Turks and Caicos Islands and has played an integral part in the community for generations. Evidence of commercial exploitation (catch data) exists only from 1957, with corresponding effort as boat-days commencing from 1966.

The fishery shows high annual variations in landings (Fig. 1), probably related to changes in recruitment and stock size as Medley and Ninnes (1997) and Bethel et al. (2000) suggested. On the other hand, the variation observed is perhaps mainly due to the dynamics of the fleet related to the high cost of the fishing effort, which displays strong direct relationship between catch and effort (Fig 2).

Figure 1. Annual reported (data collected at landing sites) and total catches (comprising of landing and local consumption data) of the Turks and Caicos spiny lobster (Panulirus argus) fishery

Figure 2. Scatter plot showing a strong correlation of catch to effort for the spiny lobster fishery of the Turks and Caicos Islands, suggesting effort has a large influence in the fluctuation in landings experienced in the fishery

Nevertheless, cpue remains relatively stable around 58 kg/boat-day from 1985 to 2001 (Fig. 3), while fishing effort fluctuations cyclically with variability coefficients for the same period of 33.6 percent, 28.7 percent, and 17.7 percent for catch, effort and cpue respectively.

Figure 3. Annual variations in effort and cpue for the spiny lobster (Panulirus argus) fishery of the Turks and Caicos Islands

Size Composition of Catch

Analysis of size composition data of lobsters randomly sampled (at landing sites prior to processing) for the period 1989-1998 suggest that approximately 41.3 percent of the landings in numbers are comprised of undersized lobsters (Fig. 4). These numbers of undersized lobsters convert to 22.1 percent of the catch in weight, which is assumed to have been rejected by the processing plants and is possibly sold for local consumption. This assumption is further corroborated by the differences in size composition sampled compared to that of size composition processed and export by the processing plants (Fig. 5). This figure matches quite well with the difference between reported and total estimated catch (Fig. 1) calculated to be 21.6 percent for the same period of available size composition data (1989-1998). The current situation could be worse, taking into account that the difference between reported and total estimated catch is 37.7 percent for the period 1999-2001.

Figure 4. Mean size composition of catch in numbers of spiny lobster (Panulirus argus) for the period 1989-1998 in the fishery of the Turks and Caicos Islands. The vertical line shows minimum legal size of 83 mm

Figure 5. Relative length frequency distributions from sampling data of catch prior to processing and from export size categories for the period 1990-1994. The difference of 43.3 percent, which converts to 22.1 percent of the catch in weight, is believed to be sold for local consumption

Status of National Spiny Lobster Resource

Bio-Economic Status of Stock

A recent local consumption survey of tourist as well as the resident population was used in conjunction with annual statistics of tourism arrivals and local population in TCI to estimate total consumption for the period 1957-2001 and summed with recorded landed catch to produce total catch estimates.

The time series of total catch and reported effort was then used to fit a dynamic version of the Schaefer (1954) surplus production model to estimate population parameters (Table 1) as carrying capacity (K), intrinsic growth rate ® and catchability coefficient (q).

Table 1. Bio-economic parameters of the spiny lobster fishery of the Turks and Caicos Islands with 95 percent confidence intervals

Additionally, the parameters from fitting of the Schaefer dynamic model (Fig. 6) and economic data obtained from stratified questionnaires that were presented to the fishers and processing plant managers was used to develop the Gordon-Schaefer dynamic bio-economic model.

Figure 6. Schaefer dynamic model fitted to the observed and estimated cpue data of the spiny lobster fishery of the Turks and Caicos Islands

The bio-economic model illustrates an open-access fishery, which in fact is the current system of operation but limited to nationals. Because of the high cost of the fishery, effort at the Maximum Economic Yield (f_MEY) is much lower than effort at the Maximum Sustainable Yield (f_MSY), while effort at the Bio-economic Equilibrium (f_BE) and f_MSY are closer. At the present, the fishery is near the Maximum Sustainable Yield (MSY) level, but the current fishing effort is higher than f_MEY.

The high cost resultant from elevated effort levels has reduced the current rent derived from the fishery to an extremely low level of US$773 295, which translates to approximately US$1.97 per kg of lobster (Table 7) compared to the estimated optimum potential of approximately US$1,092,803 (US$3.61/kg lobster) at the MEY level.

Figure 7. Static and dynamic trajectories of catch of the spiny lobster fishery of the Turks and Caicos Islands. Empty dots represent observed catch at effort data, the vertical lines represent effort levels at MEY, MSY and BE respectively from left to right

Figure 8. Static and dynamic trajectories of revenues for the spiny lobster fishery of the Turks and Caicos Islands. The vertical lines represent effort levels at MEY, MSY and BE respectively from left to right

Figure 9. Static and dynamic trajectories of profit for the Turks and Ciacos spiny lobster fishery. Although biologically the fishery is still sustainable, the high level of effort within the fishery dissipates the rent among the fishers, as such the fishery is operating a level higher than the MEY

Figure 10. Static and dynamic trajectories of biomass of the spiny lobster fishery of theTurks and Caicos Islands

Figures 7-10 show variations in catch, revenues, costs, profits and biomass resulting from the application of the static (broken lines) and dynamic (solid lines) versions of the Gordon-Schaefer model, as a function of fishing effort. Filled dots represent the current situation (1999-2001) for each variable. Vertical lines from left to right show reference points for Maximum Economic Yield (MEY), Maximum Sustainable Yield (MSY) and Bio-economic Equilibrium (BE).

Table 2. Reference points and current values for some fishery indicators

The model suggest that the current catch levels (Table 7) are still within sustainable levels, however the fishery has the potential of becoming unsustainable, surpassing the f_MSY limit reference point given the current trend of increase in effective fishing effort. Should the fishery continue under the open-access system, the model predicts that the country could begin to experience negative economic results within the next five to eight years.

Figures 11-13 show projections for catch, revenues, and biomass under open-access system (solid lines) for the period 1956-2002 and with the effort reduction from 2003 to 2020. Horizontal lines represent the MEY level for each variable.

Figure 11. Projections of catch under the open-access system catch is projected to continue to decline (line with solid circles) below the catch level at the MEY (solid horizontal line), whereas with effort restrictions applied, it is forecast that catch will rebound in time (solid fluctuating line) to the MEY level. Empty dots represent observed catch

Figure 12. Under open access, profit is projected to be reduced to zero and worse to negative value (line with solid circles). However, with restriction, profit will rebound towards the level at the MEY (solid fluctuating line)

Although a catch quota strategy management could be implemented as recommended by Bethel et al. (2000), however, such management strategy by itself is limited to conferring protection to the stocks, thereby alleviating the fluctuations in catches. The use of fishing effort as a reference point would imply that at some point effort would be curbed at the reference level to provide optimum socio-economic benefit to the resource users. One fishery management tool widely used to achieve this objective by effort reduction or exclusion (e.g. limiting the number of vessels to enter the fishery) can be applied in combination with the quota system.

Figure 13. It is also projected that biomass will continue to be low under open access (line with solid circles), whereas with effort restriction, biomass will rebound to a sustainable level at the MEY (solid fluctuating line)

Depending on the possibilities, the priorities and the common objectives for users and managers, a gradual restriction in the number of licenses could be implemented to decrease the number of boats from the current level of 198 to a sustainable level of 119 over a proposed 10-year period.

Austin (1986) aptly pointed out that limiting the number of licenses itself may not prevent biological overfishing because only the apparent effort has been managed and this in fact may have negligible impact on stock protection and management. Nevertheless, if used in conjunction with attempts to limit effective effort such as technological improvements (e.g. boat size), limiting the number of licenses can assist in achieving biological and economic objectives.

Social and Economic Status and Importance of Fisheries

In terms of production, employment, exports and government revenue, the fishing industry (lobster and conch fishery) remains an important sector in the Turks and Caicos Islands. Annual value of production (including domestic consumption) is estimated at about US$4 million or about 10 percent of the country's GDP (Clerveaux, 2002).

The fishing industry despite its declining contribution to the economy still remains an integral part of the lives of the people of the Turks and Caicos Islands, providing direct employment for approximately 8 percent of the country's labour force in the harvesting (370 fishers) and processing (80 processing workers) sector. Bennett et al. (2000) and Bennett and Clerveaux (2001) recognized the fishing industry as a major employer largely replacing a national welfare system providing employment not only for the established full-time fishers, but also for a large number of part-time fishers who derive a small but significant income from fishing.

Table 3. Performance of the fisheries sector of the Turks and Caicos Islands, 1990-1999. (The Gross Domestic Production, GDP, estimates are inclusive of spiny lobster as well as queen conch fisheries)

Sources: Caribbean Development Bank estimates from Department of Environment & Coastal Resources (TCI Gov.).

The importance of the fishing industry, in particular the lobster fishery, which generates the greatest economic return is further accentuated on the lesser developed Caicos Islands, principally the Island of South Caicos. Here, the fishing industry is highly influential and acts as the core, providing economic stability maintaining the structure and cohesion of the community (Whitmarsh, 1998). Clerveaux (2002) discovered that over 75 percent of the working population on the Island of South Caicos is directly or indirectly dependent on the fishing industry (e.g. processing plant workers, fuel station, bars, clubs, shops and restaurant owners), which is most emphatically expressed during the closed season for the lobster industry.

Conclusion and Recomendations

GIVEN the lack of systematic information on size composition from sampling programmes, it is very important to reconstruct a long, historical and continuous time series of annual results of export size categories from the processing plants. It will allow modelling the population dynamics with more detailed methods. At least from now on, this data should be recorded from all the plants.

Some fishery independent indexes should be collected, as the juvenile abundance in nursery areas, and adult abundance in the fishing areas. Also the length composition and other biological data of landed lobsters must be systematically collected.

It is also important to improve compliance of the minimum legal size to avoid growth overfishing.

Despite the advances made in research, monitoring and stock status assessment, effective management of the Turks and Caicos spiny lobster fishery may not be achieved until a clearly stated policy for the management of the resource is formulated or revamped by the decision makers in collaboration with the resources users.

Such undertaking would foster amicable management goals, which do not produce conflict between political and environmental goals with consideration of the resource users. In addition, a formulated policy for the management of the fishery would direct future research of identifying other possible indicators and reference, target and limit reference points such as expected yield at the MEY, earnings per fisher, minimum income, employment, increase in GDP and rent of the fishery.

References

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