Bervoets, T.

Diet and growth of juvenile queen conch Lobatus gigas (Gastropoda: Strombidae) in native, mixed and invasive seagrass habitats

Juvenile queen conch are primarily associated with native seagrass such as Thalassia testudinum in large parts of their range in the Caribbean and the southern Gulf of Mexico. Here, a number of non-native seagrass species have been introduced including Halophila stipulacea, which is natural to the Red Sea and the Indo-Pacific. In the Caribbean, H. stipulacea often creates dense continuous mats with little or no sediment exposed, compared to native seagrass, which grows much less dense. We examined the diet and growth of juvenile conch in both native, mixed, and invasive seagrass beds using stable isotope analysis and an in situ growth enclosure experiment. Organic material in the sediment (i.e. benthic diatoms and particulate organic matter) was found to be the most important source of carbon and nitrogen for juvenile queen conch in all 3 habitats investigated, and there was a significantly higher probability of positive growth in the native seagrass compared to the invasive seagrass. Due to the importance of the organic material in the sediment as a source of nutrition for juvenile conch, limited access to the sediment in the invasive seagrass can potentially cause inadequate nutritional conditions to sustain high growth rates. Thus, it is likely that there is a negative effect on juvenile queen conch growth currently inhabiting invasive seagrass beds, compared to native seagrass beds, when other potential sources of nutrition are not available.

Date
2019
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Saba
St. Eustatius
St. Maarten

Half a year after hurricane Irma, St.Maarten

Zes maanden geleden raasde Irma, een orkaan van de zwaarste categorie, over Sint Maarten. De verwoesting was gigantisch. De bewoners pakken sindsdien de draad zo goed en zo kwaad als het gaat weer op. Maar hoe heeft de natuur zich hersteld?
[published on vroege vogels 14 Feb., 2018]

Afval

Volgens marien bioloog Tadzio Bervoets, de drijvende kracht achter de natuurbescherming op Sint Maarten, is het opruimen van al het afval nog steeds een punt van grote zorg. Op een schiereiland midden in een centraal gelegen belangrijk natuurgebied naast de hoofdstad Philipsburg, op de Nederlandse helft van het eiland, zijn twee enorme afvalhopen gemaakt. Daar wordt het vaste afval domweg gedumpt. Dat wil zeggen, voor zover het te vervoeren is. Want op verschillende plaatsen is het eiland ook veranderd in een botenkerkhof, vol kleine en grote boten die een speelbal waren geworden in de orkaan. Over de stalen boten maakt Bervoets zich nog de minste zorgen. Zolang brandstof, accuzuur en andere schadelijke stoffen uit de schepen zijn verwijderd, kunnen stalen boten een soort kunstmatige riffen worden, waar koraal op zal hechten. Maar de meerderheid van de ‘spookschepen’ is gemaakt van polyester en glasvezel. Daarop hecht geen koraal. Bovendien zullen de vezeltjes van afbrokkelende materiaal de omgeving flink blijven vervuilen wanneer de schepen niet uit het water worden gehaald.

Weer groen blad

De natuur op land heeft zich verbazend snel hersteld, constateert Bervoets. ‘De dag nadat we allemaal uit onze schuilplaatsen kwamen zag het eiland eruit als na de Apolcalyps’, vertelt Bervoets. ‘Er zat letterlijk geen groen blaadje meer aan de bomen of de planten. Door het zout dat met de wind meekwam was alles ‘verbrand’. Maar zodra het begon te regenen zag je dat de planten zich al snel herstelden. Nu hebben bijvoorbeeld veel palmbomen alweer groene bladeren.’

Koraalherstel ligt stil

Bervoets is somberder over de projecten van zijn eigen ‘Saint Maarten Nature Conservancy’. In het zeereservaat aan de zuidoostkust van het eiland had zijn organisatie koraalherstelprojecten opgezet. Niet alleen zijn de stellages van dat project allemaal weggespoeld, ook de riffen waar zijn organisatie de ‘stekjes’ vandaan haalde om het koraal te vermeerderen zijn voor 90% verdwenen.

Bervoets lobbyt op dit moment bij de Wereldbank en de Nederlandse overheid om een deel van het hulpgeld dat is toegezegd te reserveren voor natuurherstel. ‘Er zal met name een duurzame oplossing moeten komen voor het opruimen van het vaste afval, en ook voor het verbeteren van de afvalwaterzuivering. Met name op het Nederlandse deel van het eiland wordt nu veel teveel ‘lapwerk’ verricht. En dat terwijl over een paar maanden alweer een nieuw orkaanseizoen voor de deur staat.’

Date
2018
Data type
Media
Theme
Education and outreach
Geographic location
St. Maarten

Raw data of turtle nesting monitoring on St.Maarten by Nature Foundation

Raw data of turtle nest observations, including: nest identification, species, false crawls, etc.

Please contact Nature Foundation St.Maarten for more information.

Date
2019
Data type
Raw data
Theme
Research and monitoring
Geographic location
St. Maarten

Brown pelican counts on St.Maarten by Nature Foundation St.Maarten

Raw data of brown pelican counts on St.Maarten.

Counts from 2010-2012 differ in monitoring method from 2016-2019. The latter includes counts for the number of chicks on nests, fledgelings, adults in view on land and on sea.

Please contact Nature Foundation St.Maarten for more information.

 

 

 

Date
2019
Data type
Raw data
Theme
Research and monitoring
Geographic location
St. Maarten

Marine Mammals of the Northeastern Caribbean Windward Dutch Islands: Saba, St. Eustatius, St. Maarten, and the Saba Bank

Abstract:

At least 33 native species of marine mammals have been documented from the Wider Caribbean Region (WCR). For many of these species, the waters of the region serve as primary habitat for critical activities that include feeding, mating and calving. However, relatively little remains known about their biology, life history, distribution and behavior, particularly also around the windward Dutch islands (Saba, St. Eustatius and St. Maarten). In this study we compiled 84 marine mammal records for the waters of these islands, comprising 9 previously published records and 75 new records. A total of eight distinct species are documented, six of which are cetaceans. In comparison to the leeward Dutch islands (Aruba, Curaçao and Bonaire), documented strandings are few. Results suggest that whereas beaked whales and Bryde’s whale are more common around the leeward Dutch islands, humpback whales are more common around the windward Dutch islands. This study concludes that more dedicated efforts are needed to better document and understand cetacean composition, seasonality and use of the both the windward and leeward Dutch Caribbean maritime territories. Such initiatives should help further clarify any potential regional differences as well the underlying causes thereof. Several nations, including the USA, the Dominican Republic and France, have established marine mammal sanctuaries in their Caribbean waters. Declaring the Dutch EEZ as a marine mammal sanctuary would be a valuable contribution to the conservation of marine mammals in the region. 

Date
2013
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Saba
Saba bank
St. Eustatius
St. Maarten

Results of Nature Foundation Research into invasive Seagrass H. stipulacea in the Simpson Bay Lagoon

Abstract:

In February 2013 the St. Maarten Nature Foundation confirmed the presence of Halophila stipulacea, an invasive seagrass, in the Simpson Bay Lagoon. The first unconfirmed, anecdotal report of a specimen of H. stipulacea being present in the Simpson Bay Lagoon dates back to 2010, when an EIA on the construction of the Lagoon Causeway was performed.

Extensive beds of H. stipulacea were found at three different locations: Big Key, Little Key and in the southeastern part of the Lagoon. St. Maarten is currently one of only four territories where the species has been found, thus research on controlling measures in the region are still in their infancy. A dedicated, detailed mapping project will show the real extent of distribution.

Management Recommendations:

One of the areas in Simpson Bay where most specimens were found was the planned location for the causeway. The dredging of this site in the near future will result in a definite reduction of H. stipulacea. However, this is not a solution that can be implemented everywhere. Therefore an alternative remedy has to be found to ensure that the species does not gain too much foothold within the ecosystem. The possibility of seeding areas with native grasses in an attempt to control the invasion is currently being investigated.

 

Date
2013
Data type
Research report
Theme
Research and monitoring
Geographic location
St. Maarten
Author

Report on the Economic Valuation of St. Eustatius’ Coral Reef Resources

Abstract:

The St. Eustatius National Marine Park conducted an Economic Valuation of St. Eustatius’ coral reef ecosystems in the fall of 2009. This attempted to put a monetary estimate on the coral reefs surrounding Statia. Coral Reefs are one of the island’s most valuable resources; they provide a livelihood through dive tourism and fishery and provide protection from large, damaging waves caused by hurricanes. In order to properly manage the coral reef ecosystem, an economic valuation is a useful tool to determine what exactly the monetary value of a coral reef is. With an attached value, better management decisions can be made to adequately protect this most precious of resources.

In order to complete the study four questionnaires were distributed. Two dealt specifically with fisheries, one with hotel accommodations, and one with dive tourism. Data was also provided by the Statia Tourism Office. Coral reefs have direct and indirect influences on a wide range of economic factors, and the generation of data was crucial to the successful completion of this study. Data was inputted into a computer program created by the World Resource Institute and which was adjusted by STENAPA to reflect Statia’s unique ecological and economic situation.

The findings of this study have outlined that Statia’s coral reef resources provide important goods and services to the economy of the island. The revenue that the resource is able to generate through coral reef associated tourism and fishery is approximately USD $11,200,454. Although this number is high, and highlights the importance of coral reefs to the island, it also suggests that there is an increased need for conservation, so that the value does not diminish. It is therefore in the best interest of Statia to incoroporate environmental economic data to: (1) Enforce land-use and development regulations in the coastal zone, (2) Enforce strict usage of anchorage areas, (3) Incorporate economic valuation into EIAs, (4) Include economic impacts in assessing fines for damages to reefs from activities such as anchoring in the reserves, oil spills etc, (5) Weigh revenues from a growing tourism industry against long-term economic losses from environmental impacts, (6) Evaluate distributional effects (“winners” and “losers”) of proposed coastal development projects, (7) Invest in Scientific Research, (8) Increase support from the private and public sector in the Marine Park Management Authority, STENAPA. 

Date
2010
Data type
Research report
Theme
Governance
Research and monitoring
Geographic location
St. Eustatius
Author

St. Maarten Nature Foundation Lionfish Response Plan

This document serves as a reference for the controlling and management of the invasive Indo-Pacific lionfish (Pterois miles and P. volitans complex). Lionfish are expected in St. Maarten waters in the near future and can have serious detrimental affects to the island’s marine environment, particularly to the populations of both ecologically and economically important fish species. Coral reef ecosystems can also experience degradation due to predatory stress caused by lionfish on coral reef grazers such as parrotfish (Scaridae).

The invasive lionfish also poses a threat to public health; the species has fourteen venomous spines over the length of its body which can inflict a painful sting. Particularly vulnerable to lionfish envenomations are those stakeholders of the Marine Park who have the potential of coming in close contact with the species such as fishers and divers. Recreational beach goers also face the potential of being envenomated. Envenomations can be particularly dangerous to infants, the elderly, individuals with a compromised immune system and those sensitive to the venom.

Due to the nature of the invasion of aquatic species in general and lionfish more specifically, it must be realized that a complete eradication of the species is impossible, therefore this plan will seek to actively manage lionfish in St. Maarten territorial waters. The goals and objectives of this management plan are to adequately control the impact the species will have on the ecosystem level and with regards to the risk it poses to the community and to the local economy. Management goals and objectives are coordinated and communicated with different agencies to ensure local and regional cooperation, education of and outreach to stakeholders, research and management option development on the nature of the infestation, and a species control mechanism which will seek to limit the effects of species arrival.

Management actions should be clear in both the management of the species on a local level and contributing species information on a regional and international level. Management actions in this plan are divided into two stages; pre species arrival and post species arrival actions. Actions within the two stages can belong to phase one management actions, which are the first actions to be implemented, or phase two actions, which follow phase 1 actions and are continuous. Some management actions belong to both phase one and phase two management actions. The proposed management actions for the controlling of lionfish in St. Maarten waters include education and outreach on the nature and threats of the invasion, coordination with other agencies and organizations on management options, infestation research and development such as stomach content analysis and genetic sampling, planning and assessment in the form of lionfish action protocols and lionfish sweeps, and specimen control mechanisms such as species collection and eventual culling.

Appreciation is expressed to all those who assisted with technical support regarding this Response Plan, particularly the insight gained from the St. Eustatius Lionfish Action Plan (Bervoets 2009), on which this document is based, during the Lionfish Workshop hosted by the Bonaire National Marine Park in cooperation with the Reef Environmental Education Foundation and funded by the Dutch Caribbean Nature Alliance, and various workshops given by Chris Flook of the Bermuda Museum and Zoo. 

Date
2010
Data type
Research report
Theme
Governance
Research and monitoring
Geographic location
St. Maarten
Author