Abu Dhabi’s sea turtle nesting sites

This video is about hawksbill turtles in the Caribbean.

From Wildlife Extra:

Abu Dhabi’s islands could gain global recognition as important marine turtle nesting sites

April 2014: Abu Dhabi’s Bu Tinah and Zirku Islands could soon become recognised around the world as important marine turtle nesting sites. The country’s Environment Agency – Abu Dhabi (EAD) has submitted a proposal to the Indian Ocean and South East Asia (IOSEA) MoU Secretariat to include the two islands in their network.

The critically endangered Hawksbill turtle (Eretmochelys imbricata) and the endangered Green turtle (Chelonia mydas) can be found in Abu Dhabi’s waters and nest on at least 17 offshore islands from mid-March to mid-June. The EAD’s aerial and field survey findings indicate that about 5,750 sea turtles inhabit Abu Dhabi’s waters during the winter season and 6,900 during the summer season.

“Our marine environment is a treasured part of our heritage, our past, our present and our future. Furthermore, marine turtles and their habitats are key indicators of the health of our environment and so this is why, at EAD, we have been closely studying, monitoring and protecting them since 1999,” said Thabit Zahran Al Abdessalaam, EAD’s Senior Advisor on Terrestrial and Marine Biodiversity.

“By having Bu Tinah and Zirku Islands included in the IOSEA Marine Turtle Site Network, this will help ensure their long-term conservation. It will also yield a range of socio-economic benefits for the local community in the Western Region, as conservation also means cleaner coastal waters, protecting the habitat used as nursery grounds for seafood species that support commercial and subsistence fisheries, and the overall protection of mangrove and reef habitat to reduce threats from coastal hazards.”

The two islands will be evaluated by the Secretariat, which is part of the United Nations Environment Programme’s Regional Office for Asia and the Pacific, who will take into consideration different factors including their ecological and biological significance, their governance as well as their regional and global representation.

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Caribbean humpback whales, video

This video says about itself:

Humpback whales while diving in Saba, Dutch Caribbean

12 Feb 2014

Once in a lifetime shot of humpback whales while diving in Saba using a GoPro 3 black. Right place at the right time.

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New plant species discovery on Caribbean island

This video says about itself:

26 Dec 2013

I was lucky to see these Leatherback turtles hatching on Zeelandia beach, St. Eustatius.

And here are the sequels to the first video.

From BioNews:

New Plant Species on St. Eustatius

23rd Jan 2014

ST. EUSTATIUS — The ongoing study of the vascular plant flora of St. Eustatius by STENAPA and the University of Puerto Rico has resulted in the discovery of a new species never described before by science, named Gonolobus aloiensis; the genus name coming from the Greek ‘gonos’ (seed) and Latin ‘lobus’ (pod) and the species name from ’Aloi’, the Arawak name for St. Eustatius, meaning cashew tree.

So new it still lacks a common name, Gonolobus aloiensis can be described as a vine from the climbing milkweed family (Asclepiadaceae). It is endemic to St. Eustatius and its discovery represents the first record of this genus for the island, expanding the endemic biodiversity of St. Eustatius with yet another species and proving that even on our small Dutch Caribbean islands, not all biodiversity has been charted yet.

The plant can be easily distinguished from the six other Lesser Antillean Gonolobus species by its shorter and narrower lobes and the presence of ‘glandular hairs’, or trichomes, on the top two-thirds of the lobes.

The Gonolobus genus is comprised of an estimated 100 – 150 species. On the Lesser Caribbean islands, around ten species of Gonolobus can be found, all endemic to the region of which eight are single island endemics. Now a ninth can be added to that list. Only occurring inside the Quill volcano crater rim, this newly discovered species has just surpassed the Statia Morning Glory as the rarest plant species within the Kingdom of the Netherlands.

Since its habitat, the walls of a dormant volcano crater, is hardly accessible, at the moment it is not possible to estimate the exact population size of G. aloiensis for conservation purposes. Possible threats include the goats that roam about the crater and the unlikely eruption of the volcano. However unlikely, at eruption the entire population of G. aloiensis would be wiped out. Therefore the authors recommend attempts be made to grow G. aloiensis in botanical gardens to ensure its preservation. To begin with, STENAPA will try to cultivate it in the Miriam C. Schmidt Botanical Garden on St. Eustatius.

Source: Krings, A.; Axelrod, F.S. (2013) Gonolobus aloiensis (Apocynaceae, Asclepiadoideae), a New Species from St. Eustatius. Systematic Botany 38(4): 1132–1137.

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Restoring mangroves of St. Maarten island

This video is called Natural Wonders of the Caribbean – Mangrove Swamps.

From BioNews, January 2014:

In May 2012, the construction of the Simpson Bay Lagoon Causeway on St. Maarten began, connecting the Princess Juliana International Airport to the eastern shore of the lagoon. Large sections of the mangrove forest present in the bay had to give way to the causeway construction. To compensate for this loss, in the initial stage of the project almost 8,000 juvenile mangroves were removed and have been replanted in the Simpson Bay Lagoon itself and at various other locations around the island.

Along with the replanting, which utilized a variety of ecosystem-based reforestation techniques, a monitoring programme was put in place to measure success. In January 2014 an area of 600 square metres was surveyed and it demonstrated that this reforestation project was working, and even one of the most successful mangrove reforestation initiatives on the island to date.

Mangrove forests are under severe pressure and disappearing at an alarming rate. It is estimated that approximately 60% of the total mangrove areas on St. Maarten have been lost. In the Simpson Bay Lagoon, all four species of mangroves are still present: Red Mangrove (Rhizophora mangle), Black mangrove (Avicennia germinans), White Mangrove (Laguncularia racemosa) and Buttonwood (Conocarpus erectus).

During the Nature Foundation’s monitoring, a number of invertebrate species that rely on mangroves in some way or another were recorded, including Queen Conch (Lobatus gigas), Red Cushion Sea Stars (Oreaster reticulata), Donkey Dung Sea Cucumber (Holothuria mexicana), and the Upside Down Jellyfish (Cassiopeia frondosa). The fact that these species are present is an encouraging sign for the overall health of the ecosystem.

Mangroves provide a filter for runoff water from the land that prevents harmful sediments from smothering coral reefs, including those of the Man of War Shoal Marine Park, just south of St. Maarten. When established successfully, the mangrove trees have the potential to become a thriving habitat for many other plants and animals as well as an important nursery for many species of fish, such as Schoolmaster (Lutjanus apodus), Gray Snapper (Lutjanus griseus), Great Barracuda (Sphyraena barracuda) and the Foureye Butterfly Fish (Chaetodon capistratus).

As a next step in this project, additional mangroves will also be planted on the western edge of the causeway landing and constant management and regular monitoring will be carried out to ensure the survivability of the mangroves planted.

St. Maarten coral: here.

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Vikings, shearwaters and Caribbean conservation

This video, from Saba island in the Caribbean, says about itself:

A second Audubon’s Shearwater has been brought to SCF for care-taking on June 9th, 2010. It was found by yachties floating apathetic near Ladder Bay. The animal seems exhausted, but it is in good health and without injuries. One can be lucky to see these elusive seabirds once in a lifetime, since they only return to shore at night. It is suspicious that in such short time 2 “Wedwegos” have been found in dire need of help.

From BioNews, December 2013:

The Vikings were a tough crowd, but according to Njal’s Saga (written in the 13th century) they were terrified by the calls and wailing of what they thought were trolls, and ‘night ravens’ along the coasts of western Scotland and Wales. Almost definitely, these creatures were Manx Shearwaters, a seabird that only visits the nesting colonies at night.

Manx Shearwaters and their slightly smaller tropical cousin, the Audubon’s Shearwater, spend the day far out to sea, and are known to dive to 35 metres to feed on squid and a variety of fish. Black above and pure white below, this 180 – 230 grams bird is about 30 centimetres in length and has a wingspan of about 70 centimetres. It is called shearwater for the way it tilts to the left or right, ‘shearing’ through the wind and taking advantage of the uplift from the winds over the sea surface. A member of the genus ‘Puffinus’, so called because the young were fat (or ‘puffing’) they were often caught and eaten with potatoes or salted and stored in barrels for the winter, or to sell. Archaeological sites throughout the Caribbean contain remains of Audubon’s Shearwaters, as historically they were an important source of protein. Even today, another seabird from a different family, and commonly known as a ‘Puffin’, is considered a delicacy on the Faeroe Islands and Iceland.

The common or English name for Audubon’s Shearwater was given for John James Audubon, the bird artist who illustrated the Birds of America and became the best known painter of American birds. But the bird’s full scientific name is Puffinus lherminieri, in honour of Felix Louis l’Herminier, a French naturalist whose father was exiled to the French colony of Guadaloupe [he later wrote a seminal paper on the structure and sternum – breast-bone - of birds, and was welcomed to France and given the title of Royal Naturalist].

The Vikings were not the only ones to be wary of these nocturnal seabirds. Throughout the Caribbean, Audubon’s Shearwater and closely related species have gained a devilish reputation because of their strange nocturnal calls. Caribbean people have used the name ‘diablotin’ or ‘devil bird’, and sometimes the locations where they would be heard is named after them, for example, Mourne Diablotin, (Devil mountain) on Dominica. Other names for these mysterious and raucous birds are onomatopoeic that phonetically try to imitate the call, thus ‘Chokwèkwè’ is sometimes used on Bonaire, Curacao, Aruba, and ‘Wedrego’ is commonly used on Saba, and St. Eustatius. The Wedrego of Saba is so deeply ingrained into the culture that it is the National bird and is shown on the island’s crest. Well, almost. In fact, the head of the bird on Saba’s crest more closely resembles the European Manx Shearwater, and perhaps the artist was more familiar with that species? But, in truth they do look very similar.

Audubon’s Shearwater are perfectly adapted for life at sea, and this includes their feet being located at the back of their body so that in combination with their wings they can propel themselves ‘flying’ underwater, chasing and then catching fish with their sharply edged beak. These perfect adaptations for feeding at sea become a liability when the bird comes ashore to breed, as they can only shuffle to their burrows after a less than delicate landing. This makes them vulnerable to predators such as cats, rats, and in the past, humans. Consequently, the Wedrego of Saba may be avoiding predators by nesting in remote areas or along precipitous cliffs where it is more difficult for predators to reach.

It is in part because of their nocturnal behaviour that these birds are relatively poorly known. However, most detailed studies of Audubon’s Shearwater within the Caribbean have taken place in the Bahamas where fortunately the nesting areas are low-lying and easy to access. In general, Audubon’s Shearwaters are thought to be declining throughout the Caribbean but there is insufficient information to confirm this view.

Coordinated by the Saba Conservation Foundation (SCF), with support from DCNA, Vogelbescherming, Kansas University, and AES Inc., studies of the Wedrego status, distribution, nesting success and threats have recently begun on Saba. However, the precipitous landscape does not make it easy. Consequently, a variety of different techniques are being used to identify where they nest, and how many individuals may be present. These methods include, comparing the habitat of areas where birds are heard calling verses those areas where there is no calling, recording their calls, and subsequently analysing them digitally to recognise males and females, and individuals. This vocalisation recognition technique (or voice recognition) assists in ‘fingerprinting’ individuals and thereby knowing the number of individuals and whether they return in subsequent years. Where feasible and safe, field surveys are being conducted in likely nesting areas and if possible we hope to use specially modified RADAR to assist in locating highly probable nesting areas. Bird RADAR has been successfully used to detect the scale and distribution of similar shearwater species on Hawaii, and is also used to inform and minimise potential bird strikes by aircraft in Israel. All these approaches have their practical challenges and it may be some time before we have any real understanding of the status of Audubon’s Shearwater in the Dutch Caribbean.

Without the very basic understanding of the shearwater’s breeding status and threats, it is difficult to know how to manage or conserve them. Nevertheless, a collaborative draft species management and conservation plan has been written with input from SCF, DCNA, Rijksdienst Caribisch Nederlands (RCN), and other groups and technical experts.

Conservation science is always a challenge and for this species, we are really in the dark. However, just as I was finishing this article, news came that nesting Audubon’s Shearwater have been found at an undisclosed location on the ABC islands. This observation is the first confirmed nesting record for this species on any of the ABC islands, and is very exciting. Hopefully, this will be the start of more findings, and a greater understanding of this mysterious nocturnal bird. Armed with more information of their conservation ecology we can assist in their becoming a more widespread, populous, and sustainable species throughout the Dutch Caribbean. Vikings beware.

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Caribbean butterflies, new research

This video says about itself:

Butterfly Farm St. Martin, Caribbean

Known as the Friendly Island, Sint Maarten/Saint Martin is the smallest piece of land shared by two countries – Holland and France. Only 36 square miles, but you will find yourself swept away by the breathtaking landscape, fluttering butterflies …

From the Dutch Caribbean Nature Alliance (DCNA) on Friday 29 November 2013:

Butterflies form a varied and interesting component of the biodiversity of the Antilles and contribute significantly to their status as a planetary hotspot of biodiversity. Of the 112 genera present in the islands, 59 have one or more endemic species. There are a total of 285 species present in the Antillean islands, of which 45% are endemic. Most of these are centred around the larger and higher islands of Cuba, Hispaniola and Jamaica. Butterfly biogeography remains an interesting and active area of study, not only because the Caribbean fauna is relatively well-documented but also because the West Indies present an area with a complex biogeographic past as well as a rich gamut of ongoing ecological processes such as isolation, immigration, differentiation, speciation, and extinction that will continue to shape the biodiversity of the region for times to come.

For five years Hannah Madden, park ranger of STENAPA, monitored the common butterflies of St. Eustatius annually during the months of January-April in four distinct habitats. Her last collection took place early 2013. All her data are now being combined with earlier collection data by Dr. Miller and Anna Rojer for St. Eustatius, Saba and St. Maarten to provide an update and full assessment of the butterflies of the three Dutch islands.

The findings are proving to be very interesting. First of all, the four different habitats on St. Eustatius proved to have markedly different butterfly faunas. These differences are consistent with what is generally known about the habitat requirements of the various species. For instance, The Quill showed notably highest representation of both nymphalids and heliconiids than the drier and windier habitats of The Mountains and the coastal northeast flanks of the Quill. Lycaenids were notably absent inside the Quill crater while hesperids were more or less equally successful in all four contrasting habitats. Pierids were also well-represented in all habitats but tended to be more abundant in the lower dryer and windier habitats of The Mountains and the lower coastal northeast flank of the Quill.

Butterfly faunal composition in four contrasting habitats of St. Eustatius. Total butterfly counts: Mountains: 2.463, Quill crater: 468, Quill southwest flank: 496, Quill northeast flank coastal: 3.469 (photo: DCNA)

The same contrasts also hold for individual species. For instance, Anaea minor was a species notably most strongly associated with the Quill. Densities in The Mountains area and in the still and humid Quill crater were a factor of four or more lower. Both Biblis hyperia and Heliconius charitonia were especially concentrated in the most wind-sheltered areas of the Quill, while Ephriades arcas was a hesperiid that was most important inside the Quill crater. New species records for Statia were also documented. These include Hypolimnas missipus and Papilio demoleus. Hypolimnas missipus occurs primarily in the Mountains area and was most seen on Gilboa and Signal Hill. The males are easier to spot than the females, though a female was also seen once on Gilboa Hill. Papilio demoleus is a recently introduced exotic species and was only found in the Lower Town area of the St. Eustatius port, with larvae on the limeberry, Triphasia trifolia. This plant of tropical southeast Asia has been introduced in tropical regions around the world for its edible berries. Papilio demoleus is relatively new to the Caribbean, but is gradually spreading. It is a known pest of citrus crops. The species may have come along to the region with imported crop plants. Island endemics are often vulnerable and rare. However, in November 2012 Debrot found the Lesser Antillean endemic butterfly Wallengrenia ophites to be abundant in the coastal areas of Venus Bay, Statia. Such abundance provides excellent opportunities to study the ecology of this poorly-known island endemic.

The butterfly species lists for St. Eustatius, Saba and St. Maarten now amount to 30, 28 and 25 species respectively. The total number of species documented for the three islands is: 39. This compares to a total of 61 species for all Leeward islands combined. Of the latter four are endemic species, nine endemic subspecies and one endemic genus. Three of the four lesser Antillean endemics are represented in the three Dutch Caribbean islands. Cluster analysis shows that the faunas of Saba and St. Eustatius cluster more closely with that of Nevis while the fauna of St. Maarten shares greatest similarity to the fauna of Anguilla, St. Barts and Barbuda.

The authors soon expect to submit the full study to a scientific journal for formal publication.

Read the entire article in BioNews.

St. Maarten Reef Survey: here.

Caribbean whales, dolphins and sharks

This video says about itself:

Whales in the Caribbean off Antigua and Barbuda

Humpback whales pass through the island chain each year giving those of us doing tours and charters something to look forward to. Yesterday we switched off the engines in very still conditions and had the pleasure of spending over 30 minutes with a mother and her calf. Some of the passengers on the boat couldn’t be held back and went over to snorkel with them. We made sure to keep good distance, but the inquisitive whales came very close to us to give us a good look.

Researchers of IMARES Wageningen UR in the Netherlands report about airplane based research, early November this year, in the Caribbean, in the sea around Aruba, Bonaire and Curaçao islands.

From the plane, they saw humpback whales, common bottlenose dolphins and rough-toothed dolphins. Also marine mammals which might be either Atlantic spotted dolphins, or pantropical spotted dolphins. These two species look very much alike from the air.

They saw sea turtles, rays and birds as well.

A whale shark was seen north of Aruba; and a basking shark north of Curaçao.

Curaçao coral reefs and sponges

This video is called Caribbean Coral Reefs.

From the Dutch Caribbean Nature Alliance (DCNA) on Wednesday 20 November 2013:

Coral reefs around the world are naturally surrounded by nutrient depleted waters. One might suspect a lack of nutrients would prohibit their growth; however, coral reefs are amongst the most biodiversity-rich marine ecosystems in the world. Charles Darwin observed this during his voyage on the Beagle in the 19th century, but only now has that phenomenon, aptly called ‘Darwin’s Paradox’, been explained.

A team of researchers has recently looked into the role of sponges on the coral reefs around Curaçao and found some surprising results. By recycling vast amounts of organic matter, it is the sponges that keep the reef alive. Bacteria have the reputation to be ‘nature’s recyclers’, but on coral reefs they are not abundant enough to serve as the recyclers of the whole reef community. Sponges were found to be bigger recyclers than bacteria and to produce nearly as many nutrients as all the primary producers, corals and algae, in a tropical reef combined.

By feeding the sponges isotope-labelled sugars, and by tracing these molecules on their journey, they found that the sugars were quickly shed to the seabed in dead cells (detritus). Within two days, the same molecules were present in snails and other lower organisms that feed on the sediment containing dead sponge cells. These organisms are in turn eaten by larger animals, and so the cycle continues.

Apart from the speed, it was the sheer volume of food turnover which took the researchers by surprise; nearly tenfold the amount that is recycled by bacteria. To illustrate this, the sponge Halisarca caerulea takes up two-thirds of its body weight in dissolved organic matter every day, but barely grows in size because old cells are continuously shed to the seabed.

Recognising this newly discovered role of sponges for these threatened and fragile ecosystems will hopefully aid coral reef conservation efforts worldwide.

Read the entire article in BioNews.

Three shipwrecks were removed from coral reefs in the Pacific. How long will it take the reefs to recover? Here.

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