Nature Foundation Researching Pollution Related Algae Bloom in Simpson Bay Lagoon

The St. Maarten Nature Foundation has been monitoring an algal bloom within sections of the Simpson Bay Lagoon over the past few weeks. Boaters in the area have been complaining to the Nature Foundation of algae clogging the intakes of their vessel engines and a few isolated fish die-offs have been occuring due to the presence of the algae.

During two research dives in the Lagoon it was established that the probable identity of the algae is likely Ulveria oxysperma and Ulva Linza, both species are indicative of an increase in pollution levels and a decrease in water quality for the wider Simpson Bay Lagoon. Based on the probable identification of the species, water quality was tested in order to determine the possible cause of the algal bloom and a correlation to water quality.

“We are a bit concerned that we have seen an increase in algae in the Lagoon, which is related to a drop in water quality and in increase in pollution levels. Our preliminary results have shown that indeed there was a drop in water quality with an increase in temperature related to us entering the hottest part of the year. We are also trying to determine whether or not the current algae bloom is related to the effects of the hundreds of boats and other types of infrastructure being sunk or damaged after Hurricanes Irma and Maria. This is definitely possible considering the type of stress the Simpson Bay Lagoon has been undergoing as an ecosystem and we expected for some time now for the environment in the Lagoon to react to that huge environmental stress. For the time being, we will keep an eye on the situation and hopefully the bloom will dissipate in a few weeks,” commented Tadzio Bervoets of the Nature Foundation.

algae in water
algae floating underwater in Simpson Bay lagoon
algae in hand
Algae from Simpson Bay lagoon

Nature Foundation Relaunches ‘Fragments of Recovery” Coral Reef Restoration Program

The Sint Maarten Nature Foundation has started to populate its first coral nursery structures again after most of the previous coral nurseries were damaged or destroyed by Hurricanes Irma and Maria. The Foundation has slowly started to implement its ‘Fragments of Recovery” coral restoration projects with installing the first two coral reef nurseries in an attempt to repopulate hurricane damaged reefs around the island with rare coral species. “The first Staghorn corals (Acropora cervicornis) have been transplanted to the coral nursery station on the dive site ‘Moonscape, close to Simpson Bay.  The two nursery ladders from the Nature Foundation are now populated with coral fragments in order to raise new coral colonies to repopulate the damaged coral reefs. In the next months, more nursery ladders will be placed and populated with Staghorn and also Elkhorn (Acropora palmata) fragments. The coral nursery will be checked and cleaned regularly to prevent algae growth and to secure optimal growth conditions for the corals. Also the growth of the coral fragments will be researched and compared with other Caribbean islands. We are asking scuba divers to keep their distance to the coral nursery as the corals are fragile,” commented Nature Foundation Projects Officer Melanie Meijer zu Schlochtern.

The Coral Nursery Project in St Maarten used to be part of the 3 year RESCQ project (Restoration of Ecosystem Services and Coral Reef Quality) funded by the European Union Best 2.0 Program. However, due to the effects caused by last year’s Hurricanes the Nature Foundation has had to step out of the project in order to focus on rebuilding and assisting Nature recover on the island; “Now that we are in a phase where we further along in our recovery we have started to relaunch our coral restoration program. We received tremendous help from the community and from the Coral Restoration, the US National and Oceanographic and Atmospheric Association (NOAA) and the Coral Reef Restoration Consortium to get our project going again. Slowly we will be adding coral in our nursery which we will eventually outplant on our reefs that were severely impacted by the Hurricanes. We estimate that we lost about80% of our coral combined,” commented Tadzio Bervoets, Nature Foundation Manager.

The Nature Foundation also received support and expert assistance from Jamaican Coral Restoration Expert Michelle McNaught during the initial stages of populating the fragments.

Photo: Coral Reef Restoration Nurseries in Sint Maarten

Sint Maarten Nature Foundation Scientifically Assess Coral Reef Impacts Post Hurricanes Irma and Maria Using GCRMN Standards

The Sint Maarten Nature Foundation has started to scientifically monitor the state of the country’s coral reefs after the passing of hurricanes Irma and Maria in September. With financial support made available by the Dutch Caribbean Nature Alliance the Foundation has started to research the state of the Country’s coral using the GCRMN method; “Reef monitoring is conducted every year to determine the health, composition and state of our reefs. We did our last monitoring in August right before Irma so we have good information which we can use to compare the impacts that the coral reefs have experienced. Right after the storms and since then we did some qualitative measurements but in the coming week using the GCRMN method we will be able to scientifically establish what those impacts are,” commented Nature Foundation Manager Tadzio Bervoets.

The Nature Foundation surveyed mainly dive sites in the Man of War Shoal Marine Protected Area and other important dive sites around the island. All measurements are conducted along a transect line and repeated five times on one dive site. First, abundance and biomass of all fish species is determined, secondly the cover of reef organisms (corals) are analyzed based on photo quadrats made during the dives and photo quadrats are assessed for coral health. Monitoring is also done looking for coral recruitments (juvenile corals) and algae coverage and height. Lastly, invertebrate species (sea urchins, sea cucumbers, lobster and conch) are counted and water quality is measured. These measurements will help better understand the impact Hurricanes Irma and Maria has had on Sint Maarten reefs. The method will also allow for the comparison between reefs on SInt Maarten and in the region.

“Coral reefs are critical to the economy of the island. Studies conducted by the Nature Foundation has shown that reefs contribute about USD$50 million to our economy annually so it is critical that we know their status and their ecological function after experiencing the strongest hurricanes on record,” concluded Bervoets.

Caption: Nature Foundation diver does research using GCRMN method (Michelle McNaught Photo)

Nature Foundation Records Worrisome Red Algae Outbreak on St Maarten Reefs

The St. Maarten Nature Foundation has been continuously monitoring the reefs for their health and to assess the underwater damage caused by Hurricane Irma. During the reef surveys held at the beginning of November, several shallower dive sites started to show a worrisome outbreak of red algae species. Especially on reefs shallower than 35 feet in depth large red algae blooms were recorded in the Marine Park and on other reefs around the island.

Blooms of red algae can hamper the regrowth of several reef species which were damaged due to hurricane Irma’s swells. Red algae are strong competitors and their fast growth rate will leave no space for important reef builders such as corals and sponges to recover. Algae blooms can be an indicator for water quality, showing a decrease in the water quality on St Maarten reefs and surroundings. Certain red algae species can also be a health issue when very abundant and close to shore. The state of our reefs is especially now worrisome as already 50% of the reef has been damaged wby Hurricane Irma.

An outbreak of red algae is probably due to increased nutrients feeding the algae and causing it to bloom. Increased nutrient input could be associated with hurricane passage or due to pollution such as sewage outflow. High hurricane winds mix the ocean water bringing nutrients from the deep, at a time when warm summer water are often nutrient depleted. The nutrients spur algae to grow, creating large blooms of algae. However, the red algae outbreak could be also related to the recent pump out of the Great Salt Pond, causing polluted water with high nutrients to flow to our reefs.

The Nature Foundation would like to warn all people, businesses and establishments to be sure no sewage flows are going into the ocean or lagoon to prevent further water deterioration.

 

Picture 2: Amphiroa and Dasya red algae species growing on parts of Elkhorn coral (Acropora palmata).

 

Picture 3: Red algae blooms found at the dive site ‘Fort Amsterdam/Little Bay’.

Nature Foundation Assesses Marine Park and Dive Sites

Due to Hurricane Irma causing significant damage to underwater life because of storm surge and strong water motion, the Sint Maarten Nature Foundation conducted initial Marine Park and Dive Site assessment to determine the level of impact underwater. Initial marine assessment was carried out from the 28th of September until the 6th of October 2017.

Several St Maarten dives sites in the Man of War Shoal Marine Park and around the island have been surveyed for reef and coral damage, marine life presence and to assess the mooring systems for dive operators. The Nature Foundation will start in depth reef monitoring in the coming weeks to determine detailed impacts.

Hurricane Irma impacted St Maarten reefs severely; large coral and sponge die offs have been recorded, especially in the lower parts of the reef. Shallower dive sites experienced direct major damage to branching corals such as Elkhorn coral (Acropora palmata). Large coral fragments have been broken off. The large and branching growth form of Elkhorn corals makes them vulnerable to strong water motions and surge.

Major indirect impacts are found on the reef and to corals due to sediment and sand cover. The strong surge and water motion of hurricane Irma caused sand and sediment to move over the reef and cover mainly deeper sections and mainly coral and sponges show large die offs. Rapid assessment s have estimated a 30% die off of the reef due to sediment cover and a total of 50% of the reef being affected by Irma generally. Especially in the Man of War Shoal Marine Park turf algae and macro algae have been ripped off the reef due to the strong surge underwater. Turf algae are the main food source for several reef fish and the disappearance could impact fish stock negatively.

Seagrass beds around the island have decreased drastically, probably ripped off by the strong current or covered by sediment, it could be a potential problem for sea turtles and other marine life which depend on it as a food source. Mainly the invasive midrib seagrass (Halophila stipulacea) disappeared; native seagrass species survived the storm more often, such as turtle grass (Thalassia testudinum) and manatee grass (Syringodium filiforme), probably due to their larger growth form and strong roots.

Fortunately several marine species were found in good health on our reefs, including sharks, stingrays, sea turtles, reef fish, octopus and morays. The Nature Foundation is very pleased to have recorded quite a lot of sea turtles surviving the hurricane. Interesting is the occurrence of sharks on our reefs, three weeks after the storm no sharks were recorded yet, however four weeks after the storm sharks were back to normal abundance. This shows that sharks are most likely looking for hurricane shelter in the deeper waters and after return to their normal habitat.

Despite the reef and coral damage, St Maarten dive sites are still great for scuba diving because of the remarkable marine life and surroundings. The Foundation still highly recommends St Maarten as a dive destination and encourages visitors to return to scuba dive. The Nature Foundation is aware of three dive boats surviving the storm and dive schools are encouraged to start operating in the near future.

EU-funded Project to replant coral on local reefs starts

COLE BAY–Nature Foundation started to populate its first coral nursery structures last week in an attempt to repopulate depleted reefs around the island with rare coral species. The first Staghorn corals (Acropora cervicornis) have been transplanted to the coral nursery station on the dive site close to Simpson Bay called “the Bridge.”

The two nursery ladders from the Nature Foundation are now populated with coral fragments in order to raise new coral colonies to repopulate the coral reefs. In the next months, more nursery ladders will be placed and populated with Staghorn and also Elkhorn (Acropora palmata) fragments.

The coral nursery will be checked and cleaned regularly to prevent algae growth and to secure optimal growth conditions for the corals. Also the growth of the coral fragments will be researched and compared with other Caribbean islands.

“We are asking scuba divers to keep their distance to the coral nursery as the corals are fragile,” said Foundation Projects Officer Melanie Meijer zu Schlochtern.

The Coral Nursery Project in St. Maarten is part of the three-year Restoration of Ecosystem Services and Coral Reef Quality RESCQ project funded by the European Union Best 2.0 Program.

The Foundation is collaborating with IMARES Wageningen UR, the Saba Conservation Foundation, Stenapa St. Eustatius, and the Turks and Caicos Reef Fund to restore coral reefs on St. Maarten, Saba, St. Eustatius and the Turks and Caicos Islands.

large elkhorn coral
Large Elkhorn coral

The project will restore Elkhorn (Acropora palmata) and Staghorn (A. cervicornis) coral reef zones by establishing a coral nursery on each of the four islands to grow coral fragments and transplantation at selected restoration sites.

Nature Foundation received support and expert assistance from Jamaican Coral Restoration Expert Michelle McNaught during the initial stages of populating the fragments. The Foundation also received assistance from Ocean Explorers in populating the first nurseries.

Coral Reefs

Coral reefs occur in warm, clear, shallow ocean habitats that are rich in life. The reef’s massive structure is formed from coral polyps.Polyps are tiny animals that live in colonies; when coral polyps grow, they leave behind a hard, stony, branching structure made of limestone. Pillar Coral (Dendogyra cylindrical), sponges and soft corals such as Sea Fans (Gorgonia sp.), Sea Whip (Pterogorgia pp.) are abundant in St. Maarten’s waters.

Fringing reefs are the most common reef type around St. Maarten. Patch reefs (small isolated reef areas) are found along the eastern, western and southern coasts and can be observed at dive sites such as Isabella Reef, One Step Beyond and Little Sister. Many upper reef slopes on the eastern part of the island have spur and groove formations (coral ridges alternated by sand channels). These can be observed as dive sites such as Spanish Rock, Molly BeDay and Hen and Chick.

conch shell
Conch shell

Coral reefs help protect the coastline from storm damage by reducing wave energy and slowing/diverting water currents. They also provide a safe shelter as well as feeding grounds for many marine animals such as fish, sponges, sea fans, shrimp, conch, lobsters, anemones, octopus, crabs, molluscs, urchins, worms and sea anemones. For some fish, such as parrotfish, the coral itself provides a source of food; others, such as sharks and barracudas live off the reef’s inhabitants and visitors.

A total of 153 species of reef fish have been recorded at St. Maarten’s dive sites; the most common are Blue Tang (Acanthurus coeruleus), Bluehead (Thalassoma bifasciatum), Sergeant Major (Abudefduf saxatilis), Spotted Goatfish (Pseudupeneus maculatus) and Ocean Surgeonfish (Acanthurus bahianus).

The most common shark species is the Blacktip Reef Shark (Carcharhinus melanopterus). Spotted Eagle Rays (Aetobatus narinari) are also present. All four Caribbean species of sea turtle can be found on St. Maarten’s reefs, cropping on soft corals and sponges: Hawksbills (Eretmochelys imbricate), Green Turtles (Chelonia mydas), Leatherbacks (Dermochelys coriacea) and Loggerheads (Caretta caretta). The latter are rare visitor.

While St. Maarten’s reefs are in good condition in comparison to other Caribbean reefs, they face a number of natural and man-made pressures. Unsustainable development on the island has resulted in the sedimentation and nutrient enrichment of the marine environment, which in turn smothers and kills reef organisms. The raised nutrient concentration from pollution stimulates the growth of algae, which can out compete hard corals for settlement space. Natural threats include storm damage, outbreak of disease, coral bleaching event.

red coral
Coral