Fisheries

The Saba Bank supports a vibrant local fishing industry. Fishing effort focuses mainly on a trap fishery, targeting lobster and deep water red fish (snapper) (Dilrosun 2000, Toller 2008, van Gerwen 2013, Boonstra 2014), as well as bottom drop lining for red fish (snapper). Other common fishing activities include hand lining and trap fishing for red hind (grouper) as well as trolling for pelagic species.

The download contains:

• presentation given by Martin de Graaf at the Saba Bank Symposium in December 2016.
• bioNews article based on the presentation 

BioNews is produced by the Dutch Caribbean Nature Alliance and funded by the Ministry of Economic Affairs.

A dedicated Saba Bank Symposium was organised by the University of Wageningen in December 2016. The Symposium was held in Den Helder and brought together researchers and conservationists from throughout the Kingdom to share their knowledge and to provide an overview of the current state of scientific knowledge about the Netherland’s largest and most remote National Park.

Among others, presentations were given on the following topics:

• Where does our interest in Saba Bank come from? by Paul Hoetjes
• State of the reefs: 3 expeditions to Saba Bank by Erik Meesters
• Fish and fisheries at Saba Bank by Martin de Graaf
• Importance of Saba Bank for local communities, by Kai Wulf
• Research by NIOZ on the Saba Bank, by Fleur van Duyl
• Coral diversity and historical collections of Saba Bank, by Bert Hoeksema
• Shark habitat use, by Erwin Winter
• Listening to the Bank: whales and dolphins, by Dick de Haan

The Symposium ended with a panel discussion on the sustainable use of the Saba Bank and what is needed to protect the Saba Bank for the future.

We have done our best to capture the wealth of information presented at the symposium for you in our BioNews letter and hope, that like us, you are impressed by the depth and diversity of the work that has been done to explore and document our largest National Park: The Saba Bank.

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BioNews is produced by the Dutch Caribbean Nature Alliance and funded by the Ministry of Economic Affairs.

Worldwide, fisheries produce ~27 million tons of by-catch yr -1 . By-catch is defined as unwanted fish that are accidentally caught, or discarded carcasses of target species. In Bonaire, N.A., by-catch is produced on a relatively small scale, by artisanal fishermen cleaning fish that they caught and discarding the remains back into the ocean. This study examines the feeding behaviors of fish in Bonaire and the effect fishermen’s by-catch has on these behaviors, and also investigates the potential for fish to learn about sites of by-catch input. This study was performed in two parts, the first assesed the effects of established by-catch sites, while the second part focused on learning behaviors of fish. Bites per minute, time of arrival to the food source and fish population data was collected at sites along Kaya Playa Lechi where fishermen were present daily. The same data was collected 30 m away from the fishermen at simulated by-catch sites, as well as at control sites where no by-catch was present. In part II, the discarding of fish was simulated at sites that do not receive it on a normal basis, to obtain observations on fish reactions to a new food source. It was found that densities and biodiversity were significantly greater at by-catch treatments vs. control treatments for part I. Bites min-1 was greatest when by-catch was present and the time of arrival data showed that the greatest proportion of fish arriving for the fishermen’s by-catch was within the first 15 s. For part II, densities and biodiversity were greater at control treatments than at simulated by-catch treatments. Bites min-1 was greater at simulation treatments, and there was a decrease in the time of arrival over the three day observation period. This data shows that relatively greater fish densities were seen at sites of food input, that fish were more aggressive when by-catch was present, and that fish can learn that to respond to sites with a consistent input of by-catch.

This student research was retrieved from Physis: Journal of Marine Science VII (Spring 2010)19: 21-26 from CIEE Bonaire.

Seasonally restricted lobster fishing, fish reserves and marine reserves.

The commercial fishery of Saba Bank, Netherlands Antilles, was assessed for six months from June 1 through November 30, 2007, by conducting port sampling interviews with Saban commercial fishermen to obtain information on fishing effort, gear usage, landings and species composition of catches. Results from our survey are compared to previous studies to provide an updated assessment of the Saba Bank commercial fishery.
 
The fishery can be summarized as follows. A small fishing fleet of approximately ten vessels operates from Fort Bay, Saba Island, and conducts small-scale commercial fishing on Saba Bank. Saban commercial fishermen may participate in either or both of two distinct types of fisheries: a lobster trap fishery and a “redfish” trap fishery. The two trap fisheries account for almost all commercial landings while other fishing methods (e.g. hook & line) make only a minor contribution to total landings from Saba Bank. Specific patterns of effort, landings and catch composition are identified within each trap fishery.
 
Lobster trap fishing is the more prevalent and economically significant Saba Bank fishery. Lobster catch rate is 0.84 lobster per trap-haul and 184 pounds per trip. Catch rates vary significantly with season. Projected annual lobster landings are 184,000 lbs (83.6 mt) with an exvessel value of US $1.3 million per year. The lobster trap fishery also harvests a diversity of “mixed fish” (shallow water reef fishes). Average catch rate of mixed fish is 0.5 pounds per traphaul and 37.8 pounds per trip, with projected annual mixed fish landings of 37,700 pounds (17.1 mt) at an ex-vessel value of US $68,700 per year.
 
The fish trap fishery targets “redfish” - an assortment of deepwater snapper species that is dominated by silk snapper, blackfin snapper, and vermilion snapper. These three lutjanid species comprise > 91 % of fish trap catch. Average catch rate of redfish in fish traps is 10 pounds per trap-haul, and 291 pounds per trip. Projected annual fish trap landings of redfish are 90,800 pounds (41.3 mt) with an ex-vessel value of US $289,000 per year. Fish trap landings also include a small quantity of mixed fish (< 9 % by weight of finfish in fish trap landings) comprised of a diversity of species but dominated by red hind and lane snapper. Catch rate of mixed fish in fish traps is 1 pound per trap haul and 27 pounds per trip.
 
Viewed as a whole, 2007 landings from Saba Bank by Saban commercial fishermen are projected to exceed 145 metric tons in 2007 with an ex-vessel value greater than US $1.6 million. Comparison to previous fisheries studies indicates that the Saba Bank commercial fishery is relatively stable in terms of total fishing effort, total landings, economic value, and fishing methods. The following trends were identified. Compared to 1999-2000, lobster catch rate in 2007 was approximately 33 % lower in terms of weight per trap-day, but there was only a small (6.3 %) reduction in total landings of lobster. A shift to smaller lobster size was not indicated by length frequencies: average carapace length was larger in 2007 (11.2 cm) than in 1999-2000 (10.7 cm). However, lobster fishing effort as measured by trap haul rate was 31 % greater in 2007 (80.9 trap-hauls per trip) than in 1999-2000 (62.0 trap-hauls per trip). We estimate that the total number of lobster traps in use on Saba Bank increased from 1,426 traps in 1999-2000 to 1,862 traps in 2007. Collectively, these findings indicate that Saba Bank fishermen of 2007 exert a greater fishing effort in order to maintain lobster landings at year 2000 levels. An increase in fishing effort coupled with a decrease in observed catch rate could suggest that lobster harvests are now at or exceed the maximum sustainable yield for Saba Bank stocks. However, more definitive conclusions about trends in lobster stock abundance are not possible owing to the limited time frame of available fisheries data sets.
 
The importance of redfish, as a percentage of total annual landings, has increased by three-fold since 2000. Yet, the Saba Bank redfish fishery is characterized by a lack of information. Stock densities are either unknown, or may be based on very optimistic calculations. The commercial fishery now harvests redfish primarily with fish traps, in contrast to hook & line fishing methods that predominated in 2000. Given that stock size remains poorly known, the current practice of harvesting almost exclusively juvenile fishes is a risky fisheries strategy. If reproductive output by silk snapper stocks is sufficiently reduced by harvesting it may lead to abrupt population declines or even a stock crash.
 
We recommend that the following actions should be priorities for management of Saba Bank fisheries resources: establishment of a program for long-term commercial fisheries monitoring, elimination of anchoring by large vessels on Saba Bank, development of a framework for monitoring and regulating the harvest of deepwater snappers, implementation of conservation measures to protect a red hind spawning aggregation, and initiation of a study to evaluate ghost fishing by lost traps.

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

The former Netherlands Antilles consisted of Aruba, which became a distinct state in 1986, Curaçao and Sint Maarten, which became countries in 2010 with the dissolution of the Netherland Antilles, and Bonaire, Sint Eustatius and Saba, which became special municipalities of the Netherlands. Fisheries management in the Netherlands Antilles has suffered due to a lack of data collection throughout its history and significant declines in fish catches have been seen on most of the islands over recent years. This study reconstructed fish catches for 1950-2010 in the five islands that were part of the Netherlands Antilles at the dissolution (namely Curaçao, Sint Maarten, Bonaire, Sint Eustatius and Saba) including artisanal, subsistence and recreational sectors that may be overlooked in catches officially reported to the FAO. This required disaggregation of FAO reported landings data previously reported only as ‘Netherlands Antilles’ into their constituent entities, using an assumption based approach. As a result of this process, there were two islands which had a total reconstructed catch that was less than their assumed FAO reported baseline. Overall, Curaçao was 2.2 times its baseline; Bonaire 2.9 times; Saba 6.6 times; Sint Eustatius 0.86 times (i.e., total is smaller than the baseline); and Sint Maarten 0.38 times. However, the total reconstructed catch for all five islands combined was 1.9 times the data reported by the FAO on behalf of the former Netherlands Antilles. In Bonaire and Curaçao, the dominant taxa were wahoo (Acanthocybium solandri), dolphinfish (Coryphaenidae) and tunas (Thunnus albacares and Thunnus atlanticus), with barracuda (Sphyraena barracuda) also being important in Bonaire. . In Saba, Sint Eustatius and Sint Maarten, snappers (Lutjanidae) and Caribbean spiny lobster (Panulirus argus) were the most dominant taxa, with groupers (Serranidae) also proving to be important. The study emphasizes the need for more comprehensive and accurate fisheries monitoring on all of the islands.

Programmes are beginning in Bonaire and Curaçao, although it will be several years before useful trends can be observed.

This deskstudy gives a review of small pelagic fish species and fisheries in the Dutch Caribbean, specifically species which distributions exceed the national boundaries and where international cooperation in research and management is required. The need for this study was recently identified as a high priority action in the 2010 EEZ management plan written for the Dutch Ministry of Economic Affairs. A list of schooling pelagic species with maximum sizes of 40 cm was prepared, based on the occurrence in waters deeper than 200m, in the Dutch Caribbean and Wider Caribbean Area. As a next step the (importance for) the fisheries and biology is described with a focus on the following four species (groups): Sardines (Sardinella aurita), Scads (Carangidae), Anchovy (Engraulidae) and Flyingfishes, in particular Hirundichthys speculiger and Cheilopogon cyanopterus. A fifth group, consisting of clupeids (Clupidae) and halfbeaks (Hemiramphidae) are not truly pelagic because of their association with reefs and coastal distribution, but are locally abundant and important as bait fish.

From a management perspective, small pelagic fish in the Caribbean can be divided into three groups: (1) Species with pelagic behaviour, but coastally bound. 10-20 species, wide spread in the region, locally abundant and targeted as bait fish. This group consists of Carangidae, Clupeidae, Engraulidae and Hemiramphidae. These can be monitored in local sea going surveys because the species are more or less coastal (<less than 20 km). However, catches of small pelagic species are not monitored or surveyed, hence it is often not clear what species are involved. An appropriate survey method to monitor abundance of schooling pelagic fish is echo integration. (2) True pelagic (oceanic) species: all flying fishes, wide spread in the region. Heavily targeted as bait fish, locally for human consumption (Barbados). They are clearly crossing boundaries of EEZ’s in the region. The species involved are wide spread and due to their behaviour difficult to monitor by means of a fisheries independent, sea going survey. (3) Sardinella aurita, off shore distribution, limited to an area of upwelling off the coast of Venezuela. The monitoring of the stock is a Venezuelan appointment, although at the margins, some EEC boundaries are crossed (Columbian, Dutch).

Given the importance for the ecosystem from a Dutch perspective the main focus for further research in the Dutch EEZ, should be given to coastal pelagic species in the pelagic area’s adjacent to coastal reef zones around the archipelagos. This implies no international coordination for this group in the executional phase of the survey. The second group – flyingfishes - requires more international cooperation. This group should be surveyed within ecosystem focussed surveys, running multiple methodologies like visual observations of birds and mammals, biological sampling of fish and hydrographical observations.

The potential for a small pelagic fishery in the Dutch EEZ is discussed. Direct consumption of small pelagic fish, rather than using it in the reduction sector, is more efficient from a biological and an economical point of view. For the Dutch EEZ, as a first step a (bio-)economic study into the potential of the development of a sustainable fishery for small pelagic fish in the Dutch EEZ could be initiated. The flyingfish fishery in Barbados could be used as an example or a reference. Depending on the presence of local pelagic resources, such a study should not merely focus on flying fish but should include all small pelagic fish. The Barbados flying fish fishery could also be used as an example for a local experimental fisheries project.

Finally it is recommended to start collecting data in the pelagic area’s adjacent to coastal reef zones by yearly fisheries independent sea going surveys. The best survey technique for small pelagic fish is fisheries acoustics. However, a holistic approach, incorporating observations of multiple trophic levels, using different strategies within a single survey would be highly preferable. This means that such a survey should be combined with systematic visual observations of seabirds and cetaceans as well as the collection of zooplankton and environmental data. 

The former Netherlands Antilles consisted of Aruba, which became a distinct state in 1986, Curaçao and Sint Maarten, which became countries in 2010 with the dissolution of the Netherland Antilles, and Bonaire, Sint Eustatius and Saba, which became special municipalities of the Netherlands. Fisheries management in the Netherlands Antilles has suffered due to a lack of data collection throughout its history and significant declines in fish catches have been seen on most of the islands over recent years. This study reconstructed fish catches for 1950-2010 in the five islands that were part of the Netherlands Antilles at the dissolution (namely Curaçao, Sint Maarten, Bonaire, Sint Eustatius and Saba) including artisanal, subsistence and recreational sectors that may be overlooked in catches officially reported to the FAO. This required disaggregation of FAO reported landings data previously reported only as ‘Netherlands Antilles’ into their constituent entities, using an assumption based approach. As a result of this process, there were two islands which had a total reconstructed catch that was less than their assumed FAO reported baseline. Overall, Curaçao was 2.2 times its baseline; Bonaire 2.9 times; Saba 6.6 times; Sint Eustatius 0.86 times (i.e., total is smaller than the baseline); and Sint Maarten 0.38 times. However, the total reconstructed catch for all five islands combined was 1.9 times the data reported by the FAO on behalf of the former Netherlands Antilles. In Bonaire and Curaçao, the dominant taxa were wahoo (Acanthocybium solandri), dolphinfish (Coryphaenidae) and tunas (Thunnus albacares and Thunnus atlanticus), with barracuda (Sphyraena barracuda) also being important in Bonaire. . In Saba, Sint Eustatius and Sint Maarten, snappers (Lutjanidae) and Caribbean spiny lobster (Panulirus argus) were the most dominant taxa, with groupers (Serranidae) also proving to be important. The study emphasizes the need for more comprehensive and accurate fisheries monitoring on all of the islands. Programmes are beginning in Bonaire and Curaçao, although it will be several years before useful trends can be observed. 

Findings on Marine Turtles
·         Migration routes to and from nesting sites (typically index beaches) are variously known in the Caribbean, increasingly from satellite telemetry and studies of genetics. Without doubt the WWF priority areas are connected to each other, as well as to others in the Caribbean and to the high seas, especially the Sargasso Sea, through their shared responsibility for marine turtles during their different life stages.
·         Nesting habitat for marine turtles in the Caribbean are reasonably well know, although data is continually accruing from existing and new projects that monitor nesting activity. The imperative is to capture and share data in a meaningful way so as to enable comparison between sites and to permit the analysis of population trends.
·         There is a growing focus on in-water monitoring which helps to shed light on foraging sites. A number of parallel efforts by coral reef researchers to monitor ecosystems also provide valuable information on coral reef health and resilience to climate change in the region. While these studies are useful in highlighting overall declines in the coral reef ecosystems upon which marine turtles depend, there was found to be lack of similar efforts to monitor seagrass habitat for marine turtles, or  water  quality  monitoring  in  what  is  a  highly  populated  region  with  increasing  coastal development that generally lacks urban environmental infrastructure.
·         MPAs in the Caribbean have not specifically been designed as a network to protect endangered marine turtles in their different life stages and habitats. There is better coverage of nesting beaches via terrestrial protected areas than of foraging sites in marine protected areas (MPAs), which also reflects the reality of competing interests from fisheries, oil exploration and infrastructure development. Effective MPAs require adequate management capacity, and enhanced enforcement capacity is a top priority need among Caribbean MPAs.
·         Threats to marine turtles are extensive. The most common threats to nesting turtles shared by the priority areas are artificial lighting, beach erosion/accretion and pollution The most common threats to foraging/migrating turtles are fisheries entanglement, bycatch and pollution. Throughout the Caribbean it is evident that financial and human resources are a major challenge for governments, NGOs and communities in taking forward marine turtle conservation efforts.
 
Findings on Sharks
·         Information relevant to sharks in the Caribbean was found to be spread throughout a wide range and a large volume of literature. The disparate sources of shark information include reports from national scientific and fisheries divisions, from regional fisheries management organizations, from multilateral  agencies,  and  from  regional  and  international  academic  institutions.   Only  one publication was found to bring together regional shark information.
·         Consultation with key shark experts indicated that much is still unknown about sharks, even for the more common shallow water species. Still less is known about pelagic sharks and their movements into and through the eco-regions of the Caribbean.
·         Information on sharks was found to be unevenly distributed amongst the priority areas covered in this inventory. More extensive information on sharks was found to exist for non-priority areas of the Caribbean, such as Venezuela and the US, than for the priority areas. The inventory serves to highlight geographical gaps in knowledge about sharks in the Caribbean, for example in relation to Cuban sharks, and these geographical could guide further investigation.
·         Insufficient data exists to determine which shark species are of possible concern in the Caribbean. Also complicating the Indices of relative abundance were found to sometimes provide conflicting information on population trends.
·         Although sharks are highly migratory, information on shark movements in the Caribbean and the Sargasso Sea comes from only a handful of sources.
·         Some landings data exists for shark fisheries and some data exists on the incidental capture of sharks in other fisheries. However, making meaningful comparisons between datasets is a complex and time-consuming task which could be undertaken with a specialist partner such as a regional fisheries management organization or a researcher.
·         There is scope to seek further input on sharks from a number of knowledgeable experts who were willing to contribute but were unavailable for consultation in the timeframe of this inventory.
·         Some of the information that was compiled in the course of the inventory was found to be old and/or limited in its coverage. Expert consultation raised a number of doubts about key references such as IUCN classification of sharks. There is a fundamental need to validate the presence of sharks in the region and assess their population status. Recommended follow-up to this inventory could be key local informant interviews with fishers and relevant local experts in each of the priority areas about shark sightings, catch and bycatch.
·         A key step towards effective management of Caribbean Sharks would be a meeting of regional shark scientists and experts to share data, assess its application to conservation and sustainable use, and to develop a strategy for addressing significant gaps in knowledge. Such a meeting focused on Caribbean sharks has not yet been achieved.
 
Recommendations on GIS
·         Continue GIS data scoping and the collection of existing information from organisations working on similar initiatives. Invest in understanding existing governance frameworks and building partnerships for future collaboration with other regional fisheries management organisations, BINGOs (TNC and ICUN),  Universities  (UWI,  CERMES),  local  and  regional  NGOs  (see  Mahon  et  al.  2013  for  full Caribbean governance review), with a view to developing a data sharing agreement with key partners. This would enable continued sharing of GIS data collected and produced with others practitioners working the region.
·         Construct a Geodatabase that addresses WWF’s strategic priorities in the Caribbean region and which fills gaps in existing GIS information for these priorities. This could provide a valuable spatial synthesis of several types of information relevant to the priority areas.
·         The largest GIS data gap is in relation to sharks. There are a number of studies on sharks (i.e. NOAA fisheries observer boats, Fisheries Division’s datasets) but this data needs to be compiled and GIS data produced, which requires more significant effort than was possible within the scope of this inventory.
·         There are also opportunities to improve GIS data related to marine turtles. Turtle migration is an example of this. There are multiple initiatives by various different turtle conservation organisations and academic institutions that are tracking the migrations of marine turtles in the region, especially by satellite.  GIS data from satellite tracking from various locations in the region exists, but it has never been compiled at the regional level for large scale analysis of marine turtle migration. This task could be usefully undertaken in future, ideally in conjunction with the WIDECAST network.
·         We note that some marine turtle data used in GIS are dynamic rather than static in nature and in the interests of data integrity they would benefit from updating. For example, new information is constantly becoming available from nesting monitoring activities, both new from new projects and the ongoing activities of longer term projects. There have also been discoveries of marine turtle aggregations at foraging sites, providing new data to input to GIS. Threats to marine turtles across the region are emerging and changing, for example in relation to tourism development, and creative approaches to GIS representation of this information could be developed to assist with monitoring impacts on population status and trends.
·         In  the  course  of  this  inventory  we  explored  some  new  approaches  to  mapping  marine  turtle populations   and   trends   with   the   aim   of   assisting   interpretation   and   enhancing   strategy development. The sample maps are based on data from Bonaire and the Guianas only, since comparable datasets were either missing for the other priority areas or could not be provided in the timeframe of the inventory.  There is potential to work further with WWF on the development of new GIS layers that directly feed into the strategy development process.