Kitson-Walters, K.

Twenty-two sites across four monitoring zones of St. Eustatius’ marine ecosystem within the national marine park were assessed using the Global Coral Reef Monitoring Network Caribbean Initiative (GCRMN-Caribbean) guidelines between August and October 2019. The protocol extracted data that indicated the biomass of key fish species and overall reef health including but not limited to relative abundance of macroalgae and hard coral, coral disease prevalence, coral recruit density and rugosity to name a few. Using the Reef Health Index (McField and Kramer 2007), St. Eustatius’ coral reef ecosystem is in “Fair” condition (RHI Score = 3). Coral cover remains below 5% with a statistically insignificant increase from the previous year’s estimate (2015 = 5.19%, 2016 = 4.99%, 2017 = 4.73%, 2018 = 4.21% and 2019 = 4.57 %) with macroalgae continuing to dominate (2015 = 27.93%, 2016 = 27.92%, 2017 = 25.33%, 2018 = 23.89% and 2019 = 32.45%). Combined algal benthic cover (fleshy macroalgae, cyanobacteria and turf algae) was 80%, further securing algal dominance on Statia’s reefs. Overall increase in fish biomass and density hints at the success of the marine reserves and the spillover effect. Biomass of parrotfish, surgeonfish, groupers and snappers have been “very good” over the last 3 years. Populations of these key species are greater when compared to other Eastern Caribbean territories. Large-bodied groupers and snappers were not observed during our surveys within the St. Eustatius Marine Park except for one yellowmouth grouper observed at the Cave on the Atlantic Side. Porites astreoides, remains the dominant species on Statia’s reefs due to its successful reproductive strategy as a hermaphroditic brooder with it accounting for 34% of the species composition of observed recruits. Key reef building genera such as Orbicella spp, Montastrea and Pseudodiploria spp which have a benthic cover range between 0 – 15.57% only accounted for 0-1.2 % per species of recruits observed. This implies that the future of corals on Statia’s reefs is gravely uncertain as the abundance of new reef building recruits are too low. Stony Coral Tissue Loss Disease was the most prevalent disease observed on Statia’s reefs having been first observed in August 2019. Mitigative and restorative measures are desperately needed. Emphasis is again placed on the need to focus on diversifying coral restoration techniques that target reef building genera such as Orbicella and Psuedodiploria along with the repopulation of Diadema antillarum. D. antillarum densities recorded during this survey effort where < 1 individual/100m2.

Twenty-two sites across four monitoring zones of St. Eustatius’s marine ecosystem were assessed using the Global Coral Reef Monitoring Network Caribbean Initiative (GCRMN-Caribbean) guidelines between June and August 2018. The protocol extracted data that indicated the biomass of key fish species and overall reef health including but not limited to relative abundance of macroalgae and hard coral, coral disease prevalence, coral recruit density and rugosity to name a few. Using the Reef Health Index (McField and Kramer 2007), St. Eustatius’ coral reef ecosystem is in “fair” condition (RHI Score = 3.25). Coral cover continues to decline slowly from previous estimates (2015 = 5.19%, 2016 = 4.99%, 2017 = 4.73% and 2018 = 4.21%) with macroalgae continuing to dominate with an insignificant decrease since 2017 (2015 = 27.93%, 2016 = 27.92%, 2017 = 25.33% and 2018 = 23.89%). This decrease has been replaced by an increase in turf algae and cyanobacteria. Overall increase in fish biomass and density hints at the success of the marine reserves and the spillover effect. Herbivorous fish (Parrotfish/surgeonfish) biomass. Populations of these key species are relatively the same when compared to other Eastern Caribbean territories. Biomass of groupers and snappers have increased drastically compared to 2017 but these findings are statistically insignificant, possibly due to sampling error. Due to an increased sampling effort, two additional survey sites, benthic cover for reef building corals increased but coral cover was not affected. Porites astreoides, remains the dominant species on Statia’s reefs due to its successful reproductive strategy as a hermaphroditic brooder with it accounting for 20% of the species composition of observed recruits. Key reef building genera such as Orbicella spp, Montastrea and Pseudodiploria spp which have a benthic cover range between 0.86 – 15.31% only accounted for 0-1 % per species of recruits observed. This implies that the future of corals on Statia’s reefs is gravely uncertain as the abundance of new reef building recruits are too low. Mitigative and restorative measures are desperately needed. Focus should be placed on diversifying coral restoration techniques that target reef building genera such as Orbicella and Psuedodiploria along with the repopulation of Diadema antillarum. Diadema densities recorded during this survey effort where < 1 individual/m.

This report presents an overview of the trends in St Eustatius fisheries based on the fisheries data collected on the island during 2012-2018. The fishery on St Eustatius remains mostly conducted by small open boasts with outboard engines. The number of fishing trips carried out by the fleet increased over 2014 peaking in 2015 with roughly 100 trips per months, and subsequently decreased in the following years to an average of 25 trips per month in 2018. 

The main activity is a lobster fishery using traps, also catching a mix of reef fish. This fishery is responsible for nearly 70% of the lobster landings on St Eustatius. The trend in the annual landings in this fishery broadly follows the trends in the fishing effort, with landings reaching 30 tonnes in 2015 and decreasing to 9 tonnes in 2018. Landings of lobsters from the trap fishery show a strong seasonality with higher landings from September to March, and low landings during June-July. The abundance index (derived by modelling the landings per trip) indicates an overall increase in abundance from 2012 to 2017, and an apparent decrease in lobster abundance in 2018. The average carapace length (CL) shows interannual variations without any specific trend, but is on average 95 mm for females and 102.5 for males. This means that an average of 41% of the lobsters are landed below the legal size limit (95 mm). This problem is especially acute for females of which 56% of the landings are of sublegal size. 

The species composition of the bycatch of reef fish in the lobster traps is very diverse, and is dominated by Acanthuridae (Blue Tang, Doctorfish, Surgeonfish), Ostraciidae (Honeycomb and Scrawled Cowfish) and Serranidae (Coney and Red Hind). The trends in the reef fish bycatch in the lobster traps also followed the trend in effort, with values ranging from 1.7 to 9.9 tonnes caught per year. The biomass index calculated from the catch per trip suggests a decrease in fish abundance between 2014 and 2016 and a small increase thereafter. Length frequency data for the main fish species caught in the lobster traps do not show any notable changes over the period studied. 

The second most important fishing activities after trap fishing are scuba diving and free diving. Both activities catch lobster and fish, but while lobster and fish (mainly Coney, Red hind and Lionfish) are in equal proportion in the landings from scuba diving, landings from free diving are largely dominated by lobsters. The lobster abundance index calculated from the catches per trip in free and scuba diving shows an increase from 2012 to 2016, and a sharp decrease thereafter. This is overall the same pattern as seen in trap-caught lobsters. The difference with the trend in the abundance index calculated based on trap data might be explained by spatial and depth differences in the distribution of the fishing effort between those fisheries. Scuba divers also conduct a fishery targeted on conch, representing roughly 40% of the trips. Estimates of the annual conch landings are very variable, and likely to be fairly uncertain due to the lack of information from logbooks in some years. The mean length of the conch landed appears to be stable over time, at 24.5 cm and 23.7 cm for females and males respectively. 

Next to the traps and diving fisheries, different line fisheries are conducted on St Eustatius. A handline fishery on reef fish produced landings between 0.3 and 4.3 tonnes per year in the period 2014-2017, but with much lower estimates in 2018, mainly due to a drop in effort for this year. Large pelagic fish are also caught by trolling, with landings varying between 0.6 and 2.5 tonnes per year. 

Our main recommendations in terms of both management and research and monitoring are as follows: 

- Improve control of and compliance with lobster size-limit regulations. 

- Develop a FAD fishery management plan as part of a St. Eustatius fisheries development plan. 

- Improve port sampling monitoring and subsampling intensity to cover at least one third of the trips dedicated to each fishing metiér. 

- Conduct a closer study on both the Coney and the Red Hind. Do this by combining more intensive port sampling and fisheries independent studies on the distribution and abundance of these species around St. Eustatius. 

This report presents an overview of the trends in St Eustatius fisheries based on the fisheries data collected on the island during 2012-2018. The fishery on St Eustatius remains mostly conducted by small open boasts with outboard engines. The number of fishing trips carried out by the fleet increased over 2014 peaking in 2015 with roughly 100 trips per months, and subsequently decreased in the following years to an average of 25 trips per month in 2018.

The main activity is a lobster fishery using traps, also catching a mix of reef fish. This fishery is responsible for nearly 70% of the lobster landings on St Eustatius. The trend in the annual landings in this fishery broadly follows the trends in the fishing effort, with landings reaching 30 tonnes in 2015 and decreasing to 11 tonnes in 2018. Landings of lobsters from the trap fishery show a strong seasonality with higher landings from September to March, and low landings during June-July. The abundance index (derived by modelling the landings per trip) indicates an overall increase in abundance from 2012 to 2017, and an apparent decrease in lobster abundance in 2018. The average carapace length (CL) shows interannual variations without any specific trend, but is on average 95 mm for females and 102.5 for males. This means that an average of 41% of the lobsters are landed below the legal size limit (95 mm). This problem is especially acute for females of which 56% of the landings are of sublegal size.

The species composition of the bycatch of reef fish in the lobster traps is very diverse, and is dominated by Acanthuridae (Blue Tang, Doctorfish, Surgeonfish), Ostraciidae (Honeycomb and Scrawled Cowfish) and Serranidae (Coney and Red Hind). The trends in the reef fish bycatch in the lobster traps also followed the trend in effort, with values ranging from 2.5 to 9.9 tonnes caught per year. The biomass index calculated from the catch per trip suggests a decrease in fish abundance between 2014 and 2016 and a small increase thereafter. Length frequency data for the main fish species caught in the lobster traps do not show any notable changes over the period studied.

The second most important fishing activities after trap fishing are scuba diving and free diving. Both activities catch lobster and fish, but while lobster and fish (mainly coney, red hind and lionfish) are in equal proportion in the landings from scuba diving, landings from free diving are largely dominated by lobsters. The lobster abundance index calculated from the catches per trip in free and scuba diving shows an increase from 2012 to 2016, and a sharp decrease thereafter. This is overall the same pattern as seen in trap-caught lobsters. The difference with the trend in the abundance index calculated based on trap data might be explained by spatial and depth differences in the distribution of the fishing effort between those fisheries. Scuba divers also conduct a fishery targeted on conch, representing roughly 40% of the trips. Estimates of the annual conch landings are very variable, and likely to be fairly uncertain due to the lack of information from logbooks in some years. The mean length of the conch landed appears to be stable over time, at 24.5 cm and 23.7 cm for females and males respectively.

Next to the traps and diving fisheries, different line fisheries are conducted on St Eustatius. A handline fishery on reef fish produced landings between 1.4 and 4.9 tonnes per year in the period 2014-2017, but with much lower estimates in 2018, mainly due to a drop in effort for this year. Large pelagic fish are also caught by trolling, with landings varying between 0.5 and 2.3 tonnes per year.
Our main recommendations in terms of both management and research and monitoring are as follows:
- Improve control of and compliance with lobster size-limit regulations.
- Develop a FAD fishery management plan as part of a St. Eustatius fisheries development plan.
- Improve port sampling monitoring and subsampling intensity to cover at least one third of the trips dedicated to each fishing metiér.
- Conduct a closer study on both the Coney and the Red Hind. Do this by combining more intensive port sampling and fisheries independent studies on the distribution and abundance of these species around St. Eustatius.

Raw data of fisheries monitoring activities and analysis. 

Please read this report for the analysis and outcomes.

Based on the fisheries data collected for 2017, St. Eustatius fishery continues to be a small-scale coastal fishery as described by Sybesma et al. (1993) and de Graaf et al. (2015). Lobster and fish landings for 2017 (52 metric tonnes kg and 17 metric tonnes respectively) were considerably more when compared to the 2012-2015 results of de Graaf et al. (2015). Fishing activity across the 12 fishing zones has remained the same since 2012. No activity was recorded at the Fish Aggregation Devices for 2017. Lobster traps were the most common gear used during the period followed by SCUBA. Lobster landings are seasonal with greater landings from January to February and November to December. Morphometric data collected for the Caribbean spiny lobster from 9 % of recorded lobster fishing trips, revealed that 28 % of males and 41 % of females were undersized. The average carapace length of females (97 mm) was close to the size limit (95 mm), which is concerning. An assessment of the lobster stock may be necessary to determine stock stability as 8 % of landed females were berried. Length frequency data for mixed reef fish was collected for 26 % of fishing trips. Large grouper species were rarely observed during port sampling with red hind being the dominant overall grouper species observed showing no seasonality throughout the period based on catch composition. Surgeonfish and the small groupers accounted for 44 % of the sampled catch by number (of individuals) while squirrelfish and the small groupers accounted for 46 % by weight. Pelagic species made up 4 % of landings by weight and < 1 % by number. Parrotfish in both weight and number accounted for 3 %. Parrotfish populations appear to be in a stable state as average length of species landed were greater than the average for each species across the Caribbean. When compared to other studies across the Caribbean, the 2017 data suggest that Statia’s parrotfish population seem to experience structurally low fishing pressure. Queen conch landings have remained steady over the last five years. Assessment of the conch morphometric data (39 % of total landings) suggests that increased harvesting has not yet had a measurable impact on population structure of St. Eustatius’s queen conch stock. The proposed annual combined commercial and recreational quota for 2015-2017 (4 % of estimated population size per year) nor the precautionary limit (8 % of estimated population size) recommended by the non-detrimental findings of 2014 was not exceeded during 2015-2017.

Find the raw data for this report here.

CNSI continues to monitor the vulnerable ecosystems of St. Eustatius coordinated by Data Monitoring Officer (DMO) Kimani Kitson-Walters. Coral reef surveys are conducted in collaboration with St. Eustatius National Parks (STENAPA) using the Global Coral Reef Monitoring Network (GCRMN) Protocol. Data on the island’s fisheries are collected and assessed by the DMO with plans to automate data collection using a mobile application under the Statia Blue Project. The aim is to create sustainable practices for Statia’s fisheries while putting the fish buyers in touch with the suppliers on a “real-time” basis.

St. Eustatius’ coral reefs like many others in the Caribbean are under threat from the impact of climate change and other anthropogenic stresses. In an effort to assess the response of these fragile ecosystems, the Global Coral Reef Monitoring Network (GCRMN) supported by the International Union for Conservation of Nature and other international partners developed a standard coral reef monitoring protocol to strengthen coral reef ecosystem management in the region. This is to ensure that useful data is collected for efficient comparison across Caribbean territories.

The GCRMN protocol utilizes eight criteria for data collection on coral reef ecosystems: abundance and biomass of reef fish taxa, relative cover of hard corals and their dominant competitors, health assessment of hard corals, coral recruitment, abundance of key macro-invertebrates (lobsters, queen conch, sea urchins, sea cucumbers), water quality and three-dimensional reef structure. Data within these categories are collected at 20 sites across four monitoring zones. Two of which are marine reserves where it is prohibited to fish with all types of fishing gear except handlines.

According to the Reef Health Index, the coral reef ecosystem of St. Eustatius is in a critical condition. Statia’s coral reefs have been on the decline over the last 20 years, due to the impact of hurricanes and in particular the massive bleaching event of 2005 which reduced our coral abundance by 50 %. In 2017, corals were found to occupy 4.94% of the benthos with macroalgae continuing to dominate. The species composition of corals has also changed. Researchers studying the reefs in 1999 observed an abundance of reef-building boulder corals such as Orbicella annularis, O. faveolata, O. franksi, Montastrea cavernosa and Psuedodiploria strigosa. These accounted for 54 % of the species assemblage. Eighteen years later, they represent 34 % of the assemblage, with O. annularisnot being observed during our survey. Only M. cavernosamaintained its abundance since 1999 however, multiple colonies were observed to be experiencing some degree of bleaching. The impact on Statia’s reefs due to the reduction of these reef-building species is still unclear.

Herbivorous fish (parrotfish/surgeonfish) biomass which aid in keeping macroalgal biomass in check, has suffered a 58% reduction over the last 18 years with no clear indication for this decrease. Fishing pressure on the island has remained relatively the same during this time. The impact of this reduction is observed in the increased macroalgal cover suggesting that parrotfish were the dominant algal grazers in the past since the black urchin (Diadema antillarium) die off across the region in the 1980’s. Reports on coral reef surveys done on the island in 1999 described low macroalgal cover in the presence of very high parrotfish/surgeonfish biomass.  Grouper/snapper biomass is also poor with no large grouper species being observed on any of our survey dives. Even though these species were observed in relatively frequent numbers in 1999 at similar survey sites.

These annual surveys continue to provide insight into the state of Statia’s marine ecosystems. Bringing to our attention the need for further research into the anthropogenic drivers of coral reef degradation on the island and the development of mitigative measures.

Monitoring Statia’s Fisheries

The marine ecosystems of St. Eustatius have supported a small artisanal fishery for over 30 years with fishing effort being relatively the same during this time. In 2017, there was an average of < 1 fishing trip per day. Lobster traps are the most common gear type used followed by spearguns with SCUBA. Caribbean spiny lobster is the primary product but fish (reef and pelagic) and conch are also caught. Landed lobster are normally exported to St. Maarten but exports declined in the last quarter of 2017 due to the collapse of the tourism market on surrounding islands by Hurricanes Irma and Maria. Landed reef/pelagic fish are sold locally. Morphometric data for all catch types are collected for 20-30 % of fishing trips throughout the year. This is done to assess Statia’s fishable stocks for signs of overexploitation.

For 2017, a total of 5864 kg of lobster and 2293 kg of fish (mixed reef and pelagics) were landed on St. Eustatius. Monthly landings of lobster for ranged from 17.6 – 885.5 kg while those for fish ranged from 50.8 – 553.6 kg.Fishing effort and catch were significantly reduced for the month of September due to Hurricanes Irma and Maria. 

A morphometric assessment of the Caribbean spiny lobster landings (9 % of fishing trips) revealed that 28 % of males and 41 % of females were undersized. The average carapace length of females (97 mm) was close to the size limit (95 mm), which is concerning. Length frequency data of mixed reef fish was collected for 26 % of trips. Surgeonfish and small groupers accounted for 44% of the sampled catch by number of individuals while squirrelfish and small groupers accounted for 46 % by weight.Parrotfish in both weight and number accounted for 3 %. 

Parrotfish are an important species to monitor as it has a significant impact on reef health by keeping macroalgae in check. The species is caught by both lobster traps as by-catch and intentionally using spearguns with SCUBA. Four species (princess, redband, redtail and stoplight parrotfish) were landed by traps but only the stoplight parrotfish was recorded as being landed by SCUBA. The average length of stoplight parrotfish landed by pots (33 cm) was larger than those landed by SCUBA (29 cm). The average length of landed princess parrotfish was 27 cm, redband parrotfish 22 cm and redtail parrotfish 26 cm. According to Fishbase.org, the common size of the stoplight parrotfish is 38 cm which indicates that mature individuals are present but are smaller than commonly seen throughout the region. The other parrotfish species are slightly larger (by ≤2 cm) when compared to those in the region.

Morphometric data was collected for 39 % of the queen conch landings for 2017 (1831 individuals harvested). Analysis of the data revealed that Statia’s conch populations are sustainably harvested with no indication of overexploitation. It is currently illegal to export queen conch but local consumption is allowed. The National government is in the process of assessing the feasibility of exporting the resource which would bring increased earnings for the island. This is being done in consultation with the Convention on International Trade in Endangered Species (CITES), the regulatory body responsible for the international trade of queen conch. 

St. Eustatius’ fishable resources are currently harvested at a sustainable level due to limited fishing effort. Keeping this fishing effort in check will reduce the pressure on the island’s limited fishing grounds. This will aid in securing the resource for future generations as well as maintaining marine biodiversity. Fisheries data will continue to be collected with the support of the Ministry of Economic Affairs.

Twenty sites across four monitoring zones of St. Eustatius’s marine ecosystem were assessed using the Global Coral Reef Monitoring Network Caribbean Initiative (GCRMN-Caribbean) guidelines between June and July 2017. The protocol extracted data that indicated the biomass of key fish species and overall reef health including but not limited to relative abundance of macroalgae and hard coral, coral disease prevalence, coral recruit density and water quality to name a few. Using the Reef Health Index (McField and Kramer 2007), St. Eustatius’ coral reef ecosystem is in “critical” condition (RHI Score = 1). Coral cover continues to remain stable from previous estimates (2015 = 5.19%, 2016 = 4.99% and 2017 = 4.73%) with macroalgae continuing to dominate (2015 = 27.93%, 2016 = 27.92%, 2017 = 36.6%). Herbivorous fish (Parrotfish/surgeonfish) biomass which aid in keeping macroalgal biomass in check, has suffered a 58% reduction over the last 18 years. The impact of which is observed in the increased macroalgal cover suggesting that parrotfish were the dominant algal grazers in the past since the black urchin (Diadema antillarium) die off. Reports on coral reef surveys done on the island in 1999 described low macroalgal cover in the presence of very high parrotfish/surgeonfish biomass. Grouper/snapper biomass is also poor with no large grouper species being observed on any of our survey dives. Even though these species were observed in relatively frequent numbers in 1999 at similar survey sites. The northern reserve had the highest fish density but lowest biomass suggesting a greater number of smaller fish, possibly juveniles when compared to the other zones. The southern reserve had the greater density of larger individuals when compared to the Atlantic side suggesting that both reserves may be playing a role in maintaining fish biomass and density. The coral species assemblage on the island’s reefs has changed from being dominated by primary reef building corals such as Orbicella spp, Pseudodiploria strigosa and Montastrea cavernosa to smaller boulder corals such as Siderastrea siderea and Porites astreoides. This is probably due to the cumulative impact of the 2005 bleaching event and structural damage by multiple hurricanes, hampering the recovery process. In brief, further studies into identifying the specific drivers of coral reef degradation and potential mitigation measures on the island of St. Eustatius are needed to lessen the blow on these limited and fragile ecosystems.

Raw photo material of the 2017 reef survey using the GCRMN method.

The 20 survey sites lie within the St. Eustatius National Marine Park, which surrounds the island from the high water mark to a depth of 30 meters.  To maximize comparability across the region, GCRMN data was collected solely from forereef habitats at depths ranging from 8 – 15 meters. Sites included the industrialized harbor area along with sites with perceived lower anthropogenic influence on the north and south ends of the island. For each site 5 transects were surveyed. Photographs were taken along the 5 transect lines set for counting fish, capturing 15 images per transect line. 

Please contact the DCBD administratorfor access to the raw digital photographs.