MPA

Foraging ecology of red-billed tropicbrid phaethon aethereus in the Caribbean during early chick rearing revealed by GPS tracking

Investigating the foraging patterns of tropical seabirds can provide important information about their ocean habitat affinities as well as prey choice. Foraging studies of Red-billed Tropicbird Phaethon aethereus populations in the Caribbean are lacking. We sought to rectify this by opportunistically sampling regurgitates at nest sites on the island of St. Eustatius, Lesser Antilles, and by linking the GPS tracks of foraging adults to remotely sensed environmental variables. Diet samples were dominated by Exocoetidae (59.5%) and Belonidae (14.9%), although we were unable to identify 25.5% of samples due to digestion. Tropicbirds nesting on St. Eustatius exhibited diurnal foraging patterns, foraged in deeper waters with higher chlorophyll concentration, and consumed fewer Exocoetidae species compared to travelling behaviour. The maximum distance travelled from the colony was 953.7 km, with an average trip length of 176.8 (± 249.8) km. The biologged birds crossed multiple exclusive economic zones and marine protected areas, and on that basis, we suggest that efforts to protect and conserve this species may require transboundary collaboration throughout the wider Caribbean.

Date
2022
Data type
Scientific article
Theme
Research and monitoring
Geographic location
St. Eustatius

Saba Bank video documentary

Video documentary describing the importance of the Saba Bank as a natural resource for the island of Saba, including underwater footage and interviews with fishermen and managers.

Date
2017
Data type
Media
Theme
Education and outreach
Geographic location
Saba bank
Author
Image

Abundance and population structure of queen conch inside and outside a marine protected area: repeat surveys show significant declines

ABSTRACT: Effectiveness of a marine protected area (MPA) in supporting fisheries productivity depends upon replenishment patterns, both in supplying recruits to surrounding fished areas and having a sustainable spawning stock in the MPA. Surveys for queen conch Strombus gigas were made in 2011 at 2 locations in the Exuma Cays, The Bahamas, for direct comparison with surveys conducted during the early 1990s at Warderick Wells (WW) near the center of the Exuma Cays Land and Sea Park (ECLSP) and at a fished site near Lee Stocking Island (LSI). There was no change in adult conch density and abundance in the shallow bank environment at LSI where numbers were already low in 1991, but numbers declined 91% in the deeper shelf waters. At WW, the adult population declined 69% on the bank and 6% on the island shelf. Unlike observations made in the 1990s, queen conch reproductive behavior near LSI is now rare. Average age of adult conch (indicated by shell thickness) at LSI decreased significantly during the 20 yr period between surveys, while average age increased at WW and juvenile abundance decreased. These results show that the LSI population is being overfished and the WW population is senescing because of low recruitment. In 2011, the ECLSP continued to be an important source of larvae for down- stream populations because of abundant spawners in the shelf environment. However, it is clear that the reserve is not self-sustaining for queen conch, and sustainable fishing in the Exuma Cays will depend upon a network of MPAs along with other management measures to reduce fishing mortality. 

Date
2012
Data type
Scientific article
Theme
Research and monitoring

Mapping Benthic Habitats for Representation in Marine Protected Areas

Virtually all marine conservation planning and management models in place or proposed have in common the need for improved scientific rigour in identifying and characterising the marine habitats encompassed. An emerging central theme in the last few years has been the concept of representativeness, or representative systems of Marine Protected Areas (MPAs). The habitat classification and mapping needed to incorporate considerations of representativeness into MPA planning must logically be carried out at the same scale at which management occurs. Management of highly protected areas occurs almost exclusively at local scales or finer, independent of the reservation model or philosophy employed.

Moreton Bay, on Australia’s east coast, was selected for studies at the local scale to map and classify macrobenthic habitats. In a site scale (1 km) trial for the major habitat classification study, remote underwater videography was used to map and characterise an unusual assemblage of epibenthic invertebrates on soft sediments. The assemblage included congregations of the comatulid crinoid Zygometra cf. Z. microdiscus (Bell) at densities up to 0.88 individuals.m-2, comparable to those found in coral reef habitats. There was no correlation between the distribution of this species and commonly used abiotic surrogates depth (6 – 18 m), sediment composition and residual current. This site scale trial is the first quantitative assessment of crinoid density and distribution in shallow water soft-sediment environments. The high densities found are significant in terms of the generally accepted picture of shallow-water crinoids as essentially reefal fauna. The findings highlight the conservation benefits of an inclusive approach to marine habitat survey and mapping. Assemblages such as the one described, although they may be of scientific and ecological significance, would have been overlooked by common approaches to marine conservation planning which emphasise highly productive or aesthetically appealing habitats.

Most habitat mapping studies rely solely or in part on abiotic surrogates for patterns of biodiversity. The utility of abiotic variables in predicting biological distributions at the local scale (10 km) was tested. Habitat classifications of the same set of 41 sites based on 6 abiotic variables and abundances of 89 taxa and bioturbation indicators were compared using correlation, regression and ordination analyses. The concepts of false homogeneity and false heterogeneity were defined to describe types of errors associated with using abiotic surrogates to construct habitat maps. The best prediction by abiotic surrogates explained less than 30% of the pattern of biological similarity. Errors of false homogeneity were between 20 and 62%, depending on the methods of estimation. Predictive capability of abiotic surrogates at the taxon level was poor, with only 6% of taxon / surrogate correlations significant. These results have implications for the widespread use of abiotic surrogates in marine habitat mapping to plan for, or assess, representation in Marine Protected Areas. Abiotic factors did not discriminate sufficiently between different soft bottom communities to be a reliable basis for mapping.

Habitat mapping for the design of Marine Protected Areas is critically affected by the scale of the source information. The relationship between biological similarity of macrobenthos and the distance between sites was investigated at both site and local scales, and for separate biotic groups. There was a significant negative correlation between similarity and distance, in that sites further apart were less similar than sites close together. The relationship, although significant, was quite weak at the site scale.

Rank correlograms showed that similarity was high at scales of 10 km or less, and declined markedly with increasing distance. There was evidence of patchiness in the distributions of some biotic groups, especially seagrass and anthozoans, at scales less than 16 km. In other biotic groups there was an essentially monotonic decline in similarity with distance. The spatial agglomeration approach to habitat mapping was valid in the study area. Site spacing of less than 10 km was necessary to capture important components of biological similarity. Site spacing of less than 2.5 km did not appear to be warranted.

Macrobenthic habitat types were classified and mapped at 78 sites spaced 5 km apart. The area mapped was about 2,400 km2 and extended from estuarine shallow subtidal waters to offshore areas to the 50 m isobath. Nine habitat types were recognised, with only one on hard substrate. The habitat mapping characterised several habitat types not previously described in the area and located deepwater algal and soft coral reefs not previously reported. Seagrass beds were encountered in several locations where their occurrence was either unknown or had not previously been quantified. The representation of the derived habitat types within an existing marine protected area was assessed. Only two habitat types were represented in highly protected zones, with less than 3% of each included The study represents the most spatially comprehensive survey of epibenthos undertaken in Moreton Bay, with over 40,000 m2 surveyed. Derived habitat maps provide a robust basis for inclusion of representative examples of all habitat types in marine protected area planning in and adjacent to Moreton Bay. The utility of video data to conduct a low-cost habitat survey over a comparatively large area was also demonstrated. The method used has potentially wide application for the survey and design of marine protected areas. 

Date
2003
Data type
Other resources
Theme
Research and monitoring
Author

Patterns, causes, and consequences of marine larval dispersal

Quantifying the probability of larval exchange among marine populations is key to predicting local population dynamics and optimizing networks of marine protected areas. The pattern of connectivity among populations can be described by the measure- ment of a dispersal kernel. However, a statistically robust, empirical dispersal kernel has been lacking for any marine species. Here, we use genetic parentage analysis to quantify a dispersal kernel for the reef fish Elacatinus lori, demonstrating that dispersal declines exponen- tially with distance. The spatial scale of dispersal is an order of mag- nitude less than previous estimates—the median dispersal distance is just 1.7 km and no dispersal events exceed 16.4 km despite intensive sampling out to 30 km from source. Overlaid on this strong pattern is subtle spatial variation, but neither pelagic larval duration nor direc- tion is associated with the probability of successful dispersal. Given the strong relationship between distance and dispersal, we show that distance-driven logistic models have strong power to predict dispersal probabilities. Moreover, connectivity matrices generated from these models are congruent with empirical estimates of spatial genetic structure, suggesting that the pattern of dispersal we uncovered re- flects long-term patterns of gene flow. These results challenge as- sumptions regarding the spatial scale and presumed predictors of marine population connectivity. We conclude that if marine reserve networks aim to connect whole communities of fishes and conserve biodiversity broadly, then reserves that are close in space (<10 km) will accommodate those members of the community that are short- distance dispersers. 

Date
2015
Data type
Scientific article
Theme
Research and monitoring

The economics of expanding the Marine Protected Areas of the Cayman Islands

Quantification of the benefits humans obtain from Marine Protected Areas (MPAs) supports decision-makers by elucidating the link between the functioning of MPAs and human welfare. By conducting a residential household survey among residents in the Cayman Islands, this study assesses people’s willingness to pay for the marine environment from a perspective of cultural and recreational values. In this way the study offers a partial estimation of the total economic value of the marine environment of the Cayman Islands. Two valuation methods are applied: the contingent valuation and the choice modelling method.

Data from 384 household surveys shows that 63% of the respondents are willing to pay for additional management of the marine environment. The average amount that respondents are willing to pay per month for an improvement in a marine protection area ranges between is 12.69 CI$ and 16.55 CI$. The Cayman Islands has approximately 24,165 households, resulting in a range of the total yearly cultural and recreational value of the marine environment of between 3.7 million – 4.8 million CI$ for its residents.

The choice experiment shows that respondents especially value coral reefs and water quality as marine elements. Moreover, households who participate in fishing on average express a higher value for all attributes of marine environment covered in the experiment. The study also shows that residents from Cayman Brac value fish catch significantly more than the other sister islands and that no-take zones are less valued by older residents and people born on the Cayman Islands.

The conclusions from our study concerning public support for expansion of the MPA diverge the findings of an earlier study. While Richardson et al. (2013) concludes that levels of support range from 14% to 47% between the sister islands, our study measured much higher levels of public support ranging between 58% to 85%. Whilst Richardson et al. (2013) used public consultation, geared towards assessing people’s opinions on the intended expansion, the statement within this study was part of a larger survey and a simplification of the proposed changes presented during the public consultation. However, besides the simplification, within this study people might have been primed by previous questions in the survey, which may have led to respondents realizing what trade-offs need to be made in marine conservation.

Finally, this research reveals the presence of an anchoring/ordering effect in the valuation process. Showing respondents the choice experiment first is associated with a higher fraction of the respondents being willing to pay in the contingent valuation, and to respondents being willing to pay more in the contingent valuation, compared to respondents that were shown the contingent valuation question first. 

Date
2014
Data type
Research report
Theme
Research and monitoring
Report number
R-14/35

Caribbean parrotfish density and size inside and outside marine protected area

The direct and indirect impacts of the increase in human population, in particular the growing demand for food, as well as various aspects of climate change pose threats to the abundance of parrotfishes (Scarinae), the main coral reef grazers. One way to reduce fishing is by forming marine protected area (MPA). MPAs tend to increase the abundance of marine fish. Well-managed MPA, with effective protection from fishing, could also benefit sex-changing fish populations. The objectives of this research are to assess effects of MPAs on parrotfish abundance and biomass and how do parrotfish abundance and size in the different life phases differ between sites within MPAs and outside MPAs. Fish surveys were conducted in eight Caribbean countries (Antigua, Bonaire, Barbados, Curaçao, Dominican Republic, Jamaica, St. Lucia and St. Vincent and Grenadines (SVG)) using an underwater visual census technique. The differences between parrotfish density and size within and outside MPAs were assessed. Mean parrotfish numerical density was slightly higher at MPA sites than at non-MPA sites but this was not significant. A significant difference was found between parrotfish biomass within and without the MPAs. The abundance biomass comparison (ABC) results showed that out of 33 MPA sites, 79% had a positive index and 21% a negative W-index value. In contrast, only 49% of non-MPA sites surveyed had a positive W-index. Sites within an MPA generally had higher mean parrotfish sizes than those outside the MPA, except for the juvenile phase. The present results reinforce the belief that parrotfish abundance and biomass, which where depleted by fishing, can be increased through applying significant levels of protection. However further research is needed on the effectiveness and duration of protection which are necessary to produce desired levels of improvement in parrotfish abundance, biomass and size.

 

Date
2017
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Bonaire
Curacao

Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals

Consumer-mediated indirect effects at the community level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Leveraging the large-scale, long-term removal of sponge predators, we selected overfished sites where intensive methods, primarily fish-trapping, have been employed for decades or more, and compared them to sites in remote or marine protected areas (MPAs) with variable levels of enforcement. Sponge-eating fishes (angelfishes and parrotfishes) were counted at each site, and the benthos surveyed, with coral colonies scored for interaction with sponges. Overfished sites had >3 fold more overgrowth of corals by sponges, and mean coral contact with sponges was 25.6%, compared with 12.0% at less-fished sites. Greater contact with corals by sponges at overfished sites was mostly by sponge species palatable to sponge preda- tors. Palatable species have faster rates of growth or reproduction than defended sponge species, which instead make metabolically expensive chemical defenses. These results validate the top-down conceptual model of sponge community ecology for Caribbean reefs, as well as provide an unambiguous justification for MPAs to protect threatened reef-building corals.

An unanticipated outcome of the benthic survey component of this study
was that overfished sites had lower mean macroalgal cover (23.1% vs. 38.1% for less-fished sites), a result that is contrary to prevailing assumptions about seaweed control by herbivorous fishes. Because we did not quantify herbivores for this study, we interpret this result with caution, but suggest that additional large-scale studies comparing intensively overfished and MPA sites are warranted to examine the relative impacts of herbivorous fishes and urchins on Caribbean reefs. 

 

Date
2015
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Bonaire
Curacao
St. Eustatius

Negative effects of gardening damselfish Stegastes planifrons on coral health depend on predator abundance

On Bonaire, we studied the effects of predator abundance and habitat availability on the abundance of the threespot damselfish Stegastes planifrons, a species that creates algal gardens at the expense of live coral cover. Across 21 sites, predator biomass ranged from 12 to 193 g m−2 (mean = 55.1; SD = 49.1) and benthic cover of S. planifrons’ preferred habitat (corals of the Orbicella species complex) ranged from 2.2 to 38.0% (mean = 14.3; SD = 9.6). Across these gradients, the local abundance of S. planifrons was significantly and negatively related to preda- tor biomass, but not to habitat availability. Increased local abundance of S. planifrons corre- sponded to an increasingly larger proportion of coral colonies affected by its ‘farming behavior’, resulting in an increased prevalence of coral disease. Thus, predators indirectly affected the com- position of reef communities around Bonaire by controlling damselfish abundance. Furthermore, the abundance of S. planifrons could not be correlated with its preferred habitat, despite such cor- relations having been observed elsewhere in the Caribbean. 

Date
2015
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Bonaire

A Management Capacity Assessment of Selected Coral Reef Marine Protected Areas in the Caribbean

Abstract:

This report presents the findings of an assessment of capacity building needs for the management of marine protected areas (MPAs) in the Caribbean region. A total of 27 MPA sites in 10 countries and territories were included in the assessment, which is an initiative of NOAA Coral Reef Conservation Program (CRCP) in partnership with the Caribbean Marine Protected Area Management Network and Forum (CaMPAM). A gap analysis of existing MPA capacity documents revealed a great deal of variation in the purpose, geographic scope, methodology, and nature of capacity information that has been collected to date. As such, a broad-based comparison of existing information was challenging and would likely not provide an accurate analysis. Accordingly, for this assessment a new survey tool was developed based on a modified version of an existing NOAA Coral Reef Conservation Program MPA Management Assessment checklist (http://coralreef.noaa.gov/resources/publicationsdata/). This tool, intended to be a guided self-assessment, was used by the consultants in an interview process whereby they read through questions with site managers and then allowed the managers to self-select the answers that they deemed most appropriate for their site’s situation. Each question was followed by a more thorough discussion about why that answer was selected. The regional results demonstrate that the current perceived capacity of sites is greatest in relation to zoning/boundaries, governance, management planning, stakeholder engagement, conflict resolution mechanisms, and outreach and education. Current perceived capacity of sites is lowest in relation to alternative livelihoods, socioeconomic monitoring, and fisheries management.

Priority MPA management capacity needs as identified by managers are:

  1. enforcement (10 sites)
  2. financing (9 sites)
  3. management planning, bio-physical monitoring, socio-economic monitoring (7 sites), and
  4. MPA effectiveness evaluation, and outreach and education (6 sites).

Preferred approaches to capacity building at a regional scale are:

  1. technical support,
  2. training,
  3. more staff,
  4. learning exchanges, and
  5. higher education course.

Individual site results provide more detailed information under the “rationale” narrative sections and can inform users of more specific details of the local situation and capacity strengths, and challenges. 

Date
2011
Data type
Research report
Theme
Governance
Education and outreach
Research and monitoring