Johnson, A.E.

Fishing provides an important source of income and livelihood on the Caribbean Island of Bonaire, also many people fish for recreational purposes. A large part of the catch is composed of reef-dependent species, which rely on the health and productivity of local coral reefs. To assist decision-makers in understanding and managing these fragile ecosystems contributing to Bonairean well being the economic value of reef-dependent fisheries is determined. Furthermore, the spatial distribution of the economic value of the reef fisheries is revealed to help decision makers understand which areas of reef are most economically important from a fisheries perspectives.

By estimating the economic value of the reef fisheries, which consists of both recreational and commercial fishing, the total socio-economic value of reef fishing on Bonaire is estimated. Commercial fishing is valued using the ‘net factor income approach’. The recreational value of the reef fisheries is calculated using both the ‘choice modelling’ and the ‘market valuation’ method. The commercial and recreational values are combined to arrive at a total, annual reef-fisheries value for the Island of Bonaire. This aggregate value is then combined with spatial fisheries production data using ArcGIS to create a fisheries value map of Bonaire.

The reef-related total commercial fisheries are valued at almost $400,000 annually. The recreational fishery value is estimated at an economic value of almost $700,000 per annum. These calculations have been used to create an allocation function, which estimates the spatial distribution of the fisheries value along the coral reefs of Bonaire. This in turn can be used to support long-term decision-making for example regarding specific locations for coastal zone development and its impact on commercial and recreational fisheries. 

Peer-reviewed PHD dissertation, University of California San Diego.

This dissertation is a multi-disciplinary attempt to understand how coral reef resources can be sustainably managed. I begin by examining the peer-reviewed literature on artisanal reef fisheries, identifying gaps in knowledge, and proposing a set of priority areas for future research. Ecological examinations of trap fishing and gill nets follow. Fish trap bycatch can be dramatically reduced by the inclusion of escape gaps that allow juveniles and narrow-bodied species to escape, although catch of ecologically important herbivores remains high. Gill nets capture the few remaining apex

predators present on Caribbean coral reefs, and as such are unsustainable. The second half of the dissertation is a tripartite presentation of the results of interviews with 177 fishers and 211 professional SCUBA divers on Curaçao and Bonaire. First, I consider whether interviewees' baseline conception of a healthy reef ecosystem is actually a degraded state, and they have a "shifting baseline." Then, I evaluate interviewees' discount rates and present bias, and relate those measures to their preferred management approaches. Lastly, I contemplate how to reconcile ecosystem requirements with stakeholder preferences, and use socioeconomic information to develop a sustainable management plan

Widespread use of minimally selective fish traps has contributed to the overfishing of Caribbean coral reefs. Traps typically target high-value fish such as groupers (Serranidae and Epinephelidae) and snappers (Lutjanidae), but they also have high bycatch of ecologically important herbivores (parrotfish (Scaridae) and surgeonfish (Acanthuridae)) and non-target species. One strategy for reducing this bycatch is to retrofit traps with rectangular escape gaps that allow juveniles and narrow-bodied species to escape; yet the effectiveness of these gaps has not been thoroughly tested. On the shallow reefs of Curaçao, Netherlands Antilles, I compared the catch of traditional Antillean chevron traps (the control) to the catch of traps with short escape gaps (20 × 2.5 cm), traps with tall escape gaps (40 × 2.5 cm), and traps with a panel of large aperture mesh. With data from 190 24-h trap sets, the mean number of fish caught was 11.84 in control traps, 4.88 in short gap traps, 4.43 in tall gap traps, and 0.34 in large mesh traps. Compared to controls, traps with short or tall gaps caught significantly fewer bycatch fish (–74 and –80% respectively), key herbivores (–58 and –50% respectively), and butterflyfish (Chaetodontidae; –90 and –98% respectively). The mean length of captured fish was significantly greater in gap traps because juveniles were able to escape via the gaps. Escape gaps reduce neither the catch of high-value fish, nor the total market value of the catch. Therefore, using escape gaps could make trap fishing more sustainable without reducing fishermen’s revenues.

Fishers and divers are the major resource users of Caribbean coral reefs. On Curaçao and Bonaire, reef condition is good relative to the Caribbean average, but fishes and corals have greatly declined over the last few decades. We interviewed 177 fishers and 211 professional SCUBA divers to assess their views on the extent and causes of degradation. Fishers know fish stocks are severely depleted and declining, whereas divers were aware of declines but had “shifted baselines” and consider the reefs healthy. Fishers and divers differ in perceptions of the causes and appropriate remedies for decline. Fishers generally blame external factors such as changes in climate, currents, or industrial fishing offshore, whereas divers primarily blame overfishing and coastal development. Nevertheless, the great majority of both fishers and divers support more management of both fishing and diving. Thus the social climate is ripe for balanced and strong restrictions on both groups for reef recovery and sustainable use. Exclusion of both fishers and divers from protected areas of significant size around the islands would be a major step forward towards the long-term conservation of reef resources.

Outbreaks of Acropora and Diadema diseases in the 1970s and early 1980s, overpopulation in the form of too many tourists, and overfishing are the three best predictors of the decline in Caribbean coral cover over the past 30 or more years based on the data available. Coastal pollution is undoubtedly increasingly significant but there are still too little data to tell. Increasingly warming seas pose an ominous threat but so far extreme heating events have had only localized effects and could not have been responsible for the greatest losses of Caribbean corals that had occurred throughout most of the wider Caribbean region by the early to mid 1990s.
In summary, the degradation of Caribbean reefs has unfolded in three distinct phases:
1. Massive losses of Acropora since the mid 1970s to early 1980s due to WBD. These losses are unrelated to any obvious global environmental change and may have been due to introduced pathogens associated with enormous increases in ballast water discharge from bulk carrier shipping since the 1960s.
2. Very large increase in macroalgal cover and decrease in coral cover at most overfished locations following the 1983 mass mortality of Diadema due to an unidentified and probably exotic pathogen. The phase shift in coral to macroalgal dominance reached a peak at most locations by the mid 1990s and has persisted throughout most of the Caribbean for 25 years. Numerous experiments provide a link between macroalgal increase and coral decline. Macroalgae reduce coral recruitment and growth, are commonly toxic, and can induce coral disease.

3. Continuation of the patterns established in Phase 2 exacerbated by even greater overfishing, coastal pollution, explosions in tourism, and extreme warming events that in combination have been particularly severe in the northeastern Caribbean and Florida Keys where extreme bleaching followed by outbreaks of coral disease have caused the greatest declines.
 
In: Status and Trends of Caribbean Coral Reefs: 1970 - 2012. Jackson, J.B.C., Donovan, M.K., Cramer, K.L. Lam, W.. - Washington : Global Reef Monitoring Network, 2014 - p. 211 - 215.
 
Retreived from http://www.wageningenur.nl on April13, 2015

Abstract:

To investigate a potential relationship between financial and marine resource use decisions, we conducted a time preference experiment with 153 fishers and 197 SCUBA divers on Curaçao and Bonaire. The experiment was part of a socioeconomic survey wherein interviewees were asked about their fishing and diving practices, views on fish population and coral reef health, and preferred marine resource management approaches. We use a βδ-model to identify discounting and present bias. Divers had a mean individual discount factor (IDF) of 0.91, significantly higher than fishers' mean of 0.82. Fishers and divers had similar distributions of IDFs and present bias; overall 66% of interviewees were non-biased, 22% future-biased, and 12% present-biased. IDFs and present bias were able to predict management preferences after controlling for demographic factors. However, the effect of discount factors is unique to divers, and the effect of present bias is concentrated among fishers on Curaçao. Differences in time preferences between fishers and divers should be considered when developing management strategies. Transfer payments from the dive industry could facilitate a transition to sustainable fish- ing practices. Establishing property rights alone may not be sufficient for ensuring sustainability if fishers are present-biased and greatly discount the future. 

Abstract:

The white sea urchin, Tripneustes ventricosus, is common in shallow coastal waters of the tropical Atlantic Ocean, and is widely distributed in the Caribbean Sea. The species supports small-scale, commercially important, seasonal fisheries in several islands in the eastern Caribbean including Barbados, Martinique (France) and Saint Lucia, and minor subsistence fisheries in Grenada and Saint Vincent and the Grenadines. However, despite significant management and conservation efforts by some countries, white sea urchin population abundance has declined locally. Understanding the large fluctuations in local population size and implementing sound management practices in the white sea urchin fisheries is critical to the sustainable use of this resource in the future, and would benefit considerably from a sharing of information and management experiences. To this end, this circular has attempted to collate both published and unpublished information on the white sea urchin and its fisheries in the eastern Caribbean and perspectives on past and current management of these fisheries.