Oil spill on the coast of Tobago, following wreck of mystery barge.

An oil slick has spread over 160 km on the Caribbean Sea following the wreck of a barge off the coast of the island of Tobago on 7 February 2024. The wreck was not reported by the barge's owners, but instead was spotted by beachgoers who reported it to the Tobago Emergency Management Authority. The barge has capsized on Cove Reed, off the southern coast of the island, and oil from it has spread over reefs and beaches along the southern tip of the island, as well as spreading across the Caribbean Sea towards Grenada and Venezuela.

An aerial image of the capsized barge. Office of the Chief Secretary of Tobago.

The barge appears to have been an unmanned and unpowered vessel, and has the word 'Gulfstream' painted on its side. As an unmanned, unpowered vessel it would not have been required to register with the International Maritime Organization, nor to carry an Automatic Identification System tracker, although it would have been partnered with a manned tugboat, which should (in theory) have complied with both of these requirements.

Before and after satellite images from the Copernicus Sentinel-1 mission show the scale of the oil spill that occurred off the shores of Trinidad and Tobago’s coastline earlier this week. The vessel, identified as the Gulfstream, ran aground and overturned off the southern shores of Tobago Island. The final image of the animation, captured at 10.18 pm GMT on 14 February, shows the oil spill has travelled over 160 km westwards. The spill is moving out of Trinidad and Tobago’s marine area and into Grenada’s southernmost marine area – which could affect neighbouring Venezuela. Satellite radar is particularly useful for monitoring the progression of oil spills because the presence of oil on the sea surface dampens down wave motion. Since radar basically measures surface texture, oil slicks show up well – as black smears on a grey background. European Space Agency.

An investigation by the Trinidad and Tobago Coast Guard found that a barge identified as the Gulfstream left Panama en route for Guyana coupled to a tug called the Solo Creed on 12 January 2024, and that authorities in Guyana reported that neither vessel arrived there. The Solo Creed, identified by the Vessel Finder website as a Tanzanian registered towing vessel, which visited Aruba on 20 January, and was last detected off the coast of Venezuela on 4 February.

An image of the capsized barge on 10 February 2023. Tobago House Assembly/AFP.

The Bellingcat investigative agency has identified a double-hulled barge capable of carrying 60 000 barrels of oil (i.e. 9.5 million litres) called the Gulfstream which was coupled to a tugboat called the Marlin, operating within the United States until 2012, which appears to be a good physical match for the vessel off the coast of Tobago. The Marlin was sold to the Panamanian San Martin Group in 2014, and while there are no official records of the Gulfstream after this, Bellingcat has found photographic evidence of the two vessels operating together between Panama and Venezuela between 2015 and 2020. The Marlin was sold on to another Panamanian company, Star Goods Petroleum, in 2021, and has not transmitted its position since. The Gulfstream was observed in the Astinave shipyard in Ecuador in February 2022, but has not been sighted since. Bellingcat suspect that the renamed Marlin and Gulfstream may still be operating together, as part of a 'ghost fleet' carrying embargoed Iranian oil to Venezuela. Many oil-carrying vessels operating out of Venezuela are considered to be poorly maintained to the point of being dangerous, and the Marlin and Gulfstream, if still operating together, would be 60- and 58-years-old respectively; both vessels would have been built with a planned lifetime of 30 years.

Oil spills are potentially harmful to marine life in a variety of ways. Most obviously it can coat the outside of organisms, causing damage to external structures such as the feathers of Birds and fur of Mammals, as well as smothering many marine invertebrates and plants. It also contains a variety of chemicals which can be directly toxic upset the hormonal balance of many animals. Oil also impedes the feeding of marine organisms, coating both food and feeding organs, but provides an excellent food source for Bacteria, which can lead to Eutrophication events - dramatic increases in Bacteria numbers, which then use all the oxygen in the water, leading other organisms to asphyxiate.

Workers from state own Heritage Petroleum Oil and Gas Company, the state oil company of Trinidad and Tobago, clean up an oil spill that reached Rockly Bay beach, in Scarborough, south western Tobago. Akash Boodan/AP.

Many fishermen on the southern part of Tobago are reporting vessels and equipment damaged by exposure to oil, and beaches across the southern part of the island being forced to close to tourists at the height of the tourist season. Volunteers and local specialists have recovered about 2000 barrels of oil from beaches on Tobago, but the vessel is still leaking and will probably need to be emptied of oil before it can be refloated and the damage repaired.

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Spirobranchus spp.: Christmas Tree Worms associated with new hosts found in Puerto Rico and the Netherlands Antilles.

Caribbean Christmas Tree Worms, Spirobranchus spp., are considered host generalists in their associations with Anthozoan (Scleractinia) and Hydrozoan (Millepora) Stony Corals. As planktonic larvae, they settle on Coral surfaces and start secreting a calcareous tube to be used as a dwelling. This tube usually becomes overgrown by the host Coral (except for its opening) and may get encapsulated deep inside the Coral skeleton. In this manner, the well-protected Worms grow and survive predation and other hazards, allowing them to live for over four decades. When the host Corals are overgrown by other organisms, such as Octocorals and Sponges, these may act as secondary hosts.

In a paper published in the journal Diversity on 21 March 2020, Bert Hoeksema of the Taxonomy and Systematics Group at the Naturalis Biodiversity Center, the Groningen Institute for Evolutionary Life Sciences at the University of Groningen, and the Institute of Biology Leiden at Leiden University, Jaaziel García-Hernández of the Marine Genomic Biodiversity Laboratory at the University of Puerto Rico - Mayagüez, Godfried van Moorsel of Ecosub and the ANEMOON Foundation, Gabriël Olthof also of the Taxonomy and Systematics Group at the Naturalis Biodiversity Center, and the Institute of Biology Leiden at Leiden University, and Harry ten Hove, again of the Taxonomy and Systematics Group at the Naturalis Biodiversity Center, report two new primary hosts (Scleractinians) and two new secondary hosts (a Zoantharian Soft Coral and an Ascidian colonial Sea Squirt), discovered during recent surveys (2015–2019) in the southern and eastern Caribbean, as well as in the Greater Antilles.

The Coral–Worm associations occurred in shallow subtidal water (less than 4 m depth), with the Knobby Brain Coral, Pseudodiploria clivosa, hosting Spirobranchus giganteus at St. Eustatius in the northern Leeward Islands, and the Golfball Coral, Favia fragum, hosting both Spirobranchus giganteus and Spirobranchus polycerus at Bonaire in the southern Leeward Islands. The secondary host observations, both for Spirobranchus giganteus, involved the Zoantharian Palythoa caribaeorum at Puerto Rico and the Ascidian Trididemnum solidum at Bonaire and Curaçao. Palythoa caribaeorum represents a first record as a secondary host for a species of the order Zoantharia. Until now, the only other Anthozoan secondary hosts were species in the order Alcyonacea (subclass Octorallia), whereas Trididemnum solidum represents an entirely new host phylum, the Chordata. The only other non-Anthozoan secondary hosts known to date are Sponges (Porifera).

A Coral of Pseudodiploria clivosa at 2 m depth, Scubaqua House Reef, St. Eustatius, Eastern Caribbean (2015) hosting Spirobranchus giganteus: (a) overall view and (b) close-up. Hoeksema et al. (2020).

The two new Scleractinian hosts are both typical for shallow subtidal water near the shoreline (less than 4 m depth), where a lack of previous surveys may explain why they have not previously been reported. The new records of secondary hosts are remarkable because these encrusting Animals are known to be aggressive in competition for space with Scleractinians by allelopathy (the production of harmful biochemicals) and can be abundant on shallow reef flats and slopes, where they usually outcompete and kill Scleractinian Corals by overgrowing them. In both cases, the Christmas Tree Worms survive by withstanding this overgrowth and maintain an open space near the tube opening.

Favia fragum hosting Spirobranchus spp. at 3–4 m depth, dive site 'Front Porch', Bonaire, Southern Caribbean (2019). (a)–(c) Spirobranchus giganteus: overall view (a), overgrown tube section indicated by red arrow (b); antler-shaped opercular spines showing dark pink colouration indicated by yellow arrow (c). (d) Spirobranchus polycerus: two individuals, one showing white spines on its operculum (blue arrow). Hoeksema et al. (2020).

Hoeksema et al.'s new host records confirm two Caribbean Christmas tree worms as generalist symbionts capable of infesting a large spectrum of host Corals. They are also strong survivors when their primary hosts become overgrown by more aggressive competitors for space. Previous host records mostly concern  Spirobranchus giganteus, but Hoeksema et al. also report a new host Coral for Spirobranchus polycerus. This worm species occurs in shallow water (less than 4 m depth), whereas Spirobranchus giganteus is commonly found down to 40 m depth. Both Spirobranchus species can easily be distinguished, as Spirobranchus giganteus shows long dark pink opercular spines, whereas those of Spirobranchus polycerus are short and white. Furthermore, Spirobranchus giganteus may be larger than Spirobranchus polycerus and usually shows six to seven (maximum eight) whorls in its branchial spires, whereas Spirobranchus polycerus has two to three (maximum five).

Palythoa caribaeorum acting as a secondary host for Spirobranchus giganteus at 5 m depth, Cayo Media Luna (La Parguera Natural Reserve), Puerto Rico, Greater Antilles (2017): (a) Worm extended and (b) retracted, showing the tube opening surrounded by dead Coral; damage to the Zoantharian host caused by the operculum of the extended Worm indicated by a black arrow. Hoeksema et al. (2020).

Hoeksema et al.'s observations suggest that future surveys may discover other hosts for both Spirobranchus species with the possibility of more host overlap. Whether such host sharing is related to their phylogenetic affinities or to ecological similarities (e.g., overlapping bathymetric distributions) is an open question that merits assessment.

Trididemnum solidum acting as a secondary host for Spirobranchus giganteus in the Southern Caribbean: (a), (b) dive site 'Thousand Steps', Bonaire (2019); (c) Marie Pampoen, Curaçao, 12 m depth (2017); (d), (e) Daaibooi Bay, Curaçao (2017). Extended Worms (a), (d) and the same individuals retracted, showing an open space in front of the Worm tube mouth (b), (e). Hoeksema et al. (2020).

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A new species of Serpulid Worm from the Caribbean.

Serpulids are distinctive Polychaete Worms found throughout the world’s oceans, from the intertidal zones to the deep seas. They live in calcareous tubes, which they cement to hard substrates, and are frequently found attached to shells and rocks on the beach. However, while telling that a Worm is a Serpulid is relatively easy, telling them apart can be extremely difficult. There are currently around 350 described species of Serpulid Worms in 46 genera, however it is now known that many of the characteristics traditionally used to classify species, such as the presence or absence of an operculum (calcareous cap used to seal the entrance to the tube when the Worm is retracted) or number of chaetigers (bristle-bearing segments) are now known to vary between very closely related species, and sometimes within colonies of a single species.

In a paper published in the journal Zootaxa on 22 December 2015, Nancy Prentiss of the Division of Natural Sciences at the University of Maine at Farmington, Katerina Vasileiadou, Sarah Faulwetter and Christos Arvanitidis of the Institute of Marine Biology, Biotechnology and Aquaculture at the HellenicCentre for Marine Research and Harry ten Hove of the Naturalis BiodiversityCenter describe a new species of Serpulid Worm from the Caribbean.

The new species is named Turbocavus secretus, where ‘Turbocavus’ means ‘Hurricane Hole’, after a bay on St John Island in the US Virgin Islands where it was first discovered, and ‘secretus’ means ‘hidden’, in reference to its habit of living on the underside of rocks embedded in loose sediment.

Turbocavus secretus,aggregation of coiled tubes, in situ, on the underside of rock. Prentiss et al. (2014).

Turbocavus secretus was found living at depths of 0.25-2.0 m in Hurricane Hole and Lameshur Bays in the US Virgin Islands, and also at depths of 46-49 m off Bonaire and Klien Bonaire in the Leeward Antilles and at a depth of 50 cm in a lagoon at Santa Marta Baai on Curaçao.

Turbocavus secretus, live worm with seven thoracic chaetigers. Prentiss et al. (2014).

The largest Worms reached 87 mm in length and 1.7 mm in width, living in tubes arranged in concentric circles on the undersides of rocks. The thorax region has 7−19 chaetigers and a distinct thoracic membrane, which forms an apron around the thorax and extends over the abdomen for the length of two thoracic segments. The abdomen has up to 355 chaetigers. The crown has 19 pairs of radioles; branchial eyes are present, but the species lacks an operculum. The living worms were wight with bright red markings.

Turbocavus secretus, branchial crown (with ocellar clusters) of live worm. Prentiss et al. (2014).

Placing Turbocavussecretus on the Serpulid family tree using traditional methods would be extremely difficult, as it is variable in many features that have been traditionally used to define species. However a genetic analysis revealed that it is quite distinct from any other species for which such data is available, and apparently equally closely related to a number of different genera, so Prentiss et al. feel confident in the assignment of this species to a new genus.

Turbocavus secretus, threedimensional, false colour volume rendering of micro-CT scan: partially opened tube, exposing preserved individual. Prentiss et al. (2014).

See also…

An invasive Serpulid Worm in the La Encrucijada Biosphere Reserve, Mexico.                 The Serpulid Worm Ficopomatus uschakovi was first described from Sri Lanka in 1960. Like all Serpulid Worms is an encrusting, sessile Polychaete that secretes a tube of calcite (calcium carbonate) in which it dwells. Unlike most other Serpulids Ficopomatus uschakovi inhabits brackish waters in estuaries and lagoons rather than fully saline waters. It can form large, reef-like masses and rapidly dominates... 

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Thirteen new species of deepwater Sponges from the Caribbean Netherlands.

The shallow water reefs around Bonaire and Klein Curaçao in the Caribbean Netherlands are well studied and are considered a biodiversity hotspot, but the deeper reefs of the area are almost unknown, having been surveyed only once in 2000 by a group bioprospecting for medically interesting taxa. The Netherlands is committed to protecting and managing offshore ecosystems in the Caribbean Netherlands as part of the Exclusive Economic Zone management plan, but without a detailed understanding of the regions biodiversity this is impossible.

In a paper published in the journal Zootaxa on 29 October 2014, RobVan Soest of the Department of Marine Zoology at the Naturalis BiodiversityCenter in Leiden, Erik Meesters of the Institute for Marine Resources andEcosystem Studies in Den Helder and Leontine Becking of the Department ofEnvironmental Science, Policy and Management at the University of California,Berkeley describe thirteen new species of Sponges from deepwater reefs around Bonaire and Klein Curaçao in the Caribbean Netherlands, discovered in a series of dives by a submersible Curasub, operating from the RV Chapman as part of the Bonaire Deep Reef Expedition of 2013, carried out by the Institute for Marine Resources and Ecosystem Studies at the request of The Netherlands Ministryof Economic Affairs.

The first new species described is placed in the Homoscleromorph genus Plakinastrella and given the specific name stinapa in honour of the Stichting Nationale Parken, a non-governmental organisation managing and conserving the Bonaire National Marine Park. Plakinastrella stinapa is described from a single specimen collected from a limestone rockwall at a depth of 242 m off the coast of Bonaire. The specimen is a thick encrusting sponge, grey green in colour and covering an area of 10 x 15 cm. It had a skeleton composed of calthrops (four pointed elements), triods (three pointed elements) and diods (two pointed elements). There are twelve previously described species of Plakinastrella, of which three have been found in the Western Atlantic; from the Caribbean and off the coasts of the Carolinas and Brazil.

Plakinastrella stinapain situ on limestone rockwall west of Bonaire. Van Soest et al. (2014).

The second new species described is placed in the Demosponge genus Pachastrella and given the specific name pacoi, in honour of Paco Cárdenas, for his work on the taxonomy of tetractinellid sponges. Pachastrella pacoi is described from three specimens, one from limestone rockwall at a depth of 232 m off the coast of Cargill on Bonaire, one from sand at the base of a limestone rockwall at a depth of 159 m off the coast of Curoil Dock on Bonaire, and a third from a depth of 203 m, also off Curoil Dock. The Sponge is variable in morphology, but tends to be roughly cup-shaped, with an irregular, bumpy outer surface and a smooth inner surface. The largest specimen was 16 cm in diameter and 15 cm high. The skeleton comprises a variety of spicule morphologies in a confused mass.

Pachastrella pacoi at the base of a limestone rockwall at a depth of 159 m off the coast of Curoil Dock on Bonaire. Van Soest et al. (2014).

The third new species described is placed in the Demosponge genus Characella, and given the specific name poecillastroides, for its plate-like shape, which is reminiscent of that common in the related genus Poecillastra. Characella poecillastroides is described from a single specimen, collected from a Coral rock wall at a depth of 168 m off Curoil Dock on Bonaire. The specimen formed a thick folded plate 2-4 cm thick and covering an area of 20 x 40 cm. It was beige in colour, though its surface was greyish due to adhered sediment. It has a skeleton largely of long, needle shaped elements called oxeas, but with other elements also present. The species resembles the Barbadian Poecillastra sollasi, which has been described as intermediate between Poecillastra and Characella, but is assigned to Characella on the basis of its skeletal elements.

Characella poecillastroidesin situ off the southwest coast of Bonaire. Van Soest et al. (2014).

The fourth new species described is placed in the Demosponge genus Geodia, and given the specific name curacaoensis, meaning ‘from Curaçao’. The species is described from a single specimen, collected from a Coral rock wall at a depth of 156 m off the southwest coast of Klein Curaçao, though it is thought likely that another specimen collected at a depth of 144-153 m off the coast of Paynes Bay in Barbados in 1978 also belongs to this species. The Klein Curaçao specimen is a spherical Sponge, 5.5 cm in diameter, grey white in colour but red on its upper surface.

Geodia curacaoensis on deck. Van Soest et al. (2014).

The fifth new species described is placed in the Dermosponge genus Caminus and given the specific name carmabi, after the Caraibisch Marien Biologisch Instituut at Piscadera Baai on Curaçao. The species is described from two specimens, the first collected at a depth of between 120 m and 137 m from sand on a rock wall off the coast of Kralendijk Pier on Bonaire, and the second from a coral rock wall at a depth of 198 m off the coast of Curoil Dock, also on Bonaire. These are spherical pink sponges with an opening with a raised rim, the larger being 7 x 4 x 4 cm and the smaller 5 x 2 x 2 cm. It has a dense layer of sterrasters (speherical skeletal elements) I its cortical (skin) layer, with other elements underneath to support its shape. This is only the second species of Caminus reported from the Western Atlantic, although the first species, Caminus sphaeroconia, has been recorded from Brazil, Puerto Rico, the Virgin Islands and Barbados.

Caminus carmabi, from a coral rock wall at a depth of 198 m off the coast of Curoil Dockon Bonaire. Van Soest et al. (2014).

The sixth new species described is placed in the Demosponge genus Discodermia, and given the specific name adhaerens, meaning ‘to cling to’, a reference to its encrusting growth habit. The species is described from a single specimen collected from a Coral rock wall at a depth of 146 m off the coast of Kralendijk Pier on Bonaire. Discodermia adhaerens is a bright orange encrusting sponge, 2-3 mm in thickness but spreading over several tens of centimetres of rock. It has a skeleton of closely packed, overlapping discotriaenes (disk-shaped skeletal elements).

Discodermia adhaerens, specimen on a Coral rock wall at a depth of 146 m off the coast of Kralendijk Pier on Bonaire. Van Soest et al. (2014).

The seventh new specimen described is placed in the Demosponge genus Clathria, and subgenus Microciona and given the specific name acarnoides, due to the presence of acanthocladotylote-shaped acanthostyles (long skeletal elements with numerous spiky projections), which have only previously been recorded in members of the genus Acarnus. The species is described from a single specimen collected from a coral rock wall at a depth of 152 m off the coast of Curoil Dock on southwest Bonaire. Clathria (Microciona) acarnoides is an orange encrusting Sponge that was found covering the shell of a Mollusc.

Clathria (Microciona) acarnoides  found covering the shell of a Mollusc on a coral rock wall at a depth of 152 m off the coast of Curoil Dock on southwest Bonaire. Van Soest et al. (2014).

The eighth new species described is placed in the Demosponge Genus Antho and subgenus Acarnia and given the specific name pellita, meaning ‘forming a skin’ in reference to its encrusting habit. The species is described from a single specimen found encrusting a larger Sponge at a depth of 108 m off the coast of Kralendijk Pier on Bonaire. It is red in colour and soft, about 2 m thick and covered an area of 11 x 6 cm of the surface of the other Sponge.

Antho (Acarnia) pellita encrusting on the base of Neopetrosia eurystomata.Van Soest et al. (2014).

The ninth new species is placed in the Demosponge genus Parahigginsia and given the specific name strongylifera, in reference to its strongyle megascleres (elongate skeletal elements). The species is described from a single specimen collected from a limestone rockwall at a depth of 238 m off the coast of Bonaire. Parahigginsia strongylifera is a pale blue encrusting sponge forming a series of cone-shaped lobes, roughly 1-2 cm high. This is only the second species of Parahigginsia described, the first, Parahigginsia phakelloides being known from New Zealand and New Caladonia, and having a lamellate (layered) growth form, forming lobes up to 14 cm high.

Parahigginsia strongyliferaon a limestone rockwall at a depth of 238 m off the coast of Bonaire.Van Soest et al. (2014).

The tenth new species described is placed within the Dermosponge genus Calyx and given the specific name magnoculata, in reference to its large and conspicuous oscules. The species is described from a single specimen collected at a depth of 232 m off the southwest coast of Bonaire. Calyx magnoculata is an encrusting Sponge roughly 2 cm thick, the specimen covering roughly 11 x 16 cm of rockface and being beige in colour. It has a skeleton of tightly knit overlapping oxeas (curved needle-shaped elements). Only a single species of Calyx has previously been reported from the Western Atlantic, Calyx podatypa, from deep water off Puerto Rico and Barbados.

Calyx magnoculata shortly after collection. Van Soest et al. (2014).

The eleventh new specimen described is placed in the Dermosponge genus Neopetrosia and given the specific name dutchi in honour of Adriaan ‘Dutch’ Schriers, the owner of the Curasub, the vehicle used in the study. The species is described from a single specimen collected from sand at a depth of 217 m off the southwest coast of Bonaire. The specimen consists of a clump of white lobes 35 x 35 x 30 cm found sitting on the sand surface. It has a skeleton formed of a mesh of oxeas (curved needle-shaped elements). It is thought that specimens previously collected from Barbados should also be referred to this species.

View of submarine with collected specimen of Neopetrosia dutchi. Van Soest et al. (2014).

The twelfth new species described is also placed in the genus Neopetrosia, and given the specific name ovata, meaning ‘ovate’, in reference to the shape of the shape of the Sponge. Neopetrosia ovata is described from a single specimen collected from sand at a depth of 149 m of the southwest coast of Klein Curaçao. The specimen is a pinkish beige egg-shaped Sponge 10 cm high and 8 cm in diameter. It also has a skeleton formed of a mesh of oxeas, though less organised than that of Neopetrosia dutchi.

Neopetrosia ovata on sand at a depth of 149 m of the southwest coast of Klein Curaçao. Van Soest et al. (2014).

The thirteenth new species is also placed in the genus Neopetrosia and given the specific name eurystomata, meaning wide-mouth. Neopetrosia eurystomata is described from three specimens, two collected from sandy rubble at depths of 108 and 111 m off the coast of Kralendijk Pier on Bonaire, and one collected from sand at a depth of 88 m off Curoil Dock on Bonaire. It is vase-shaped with a wide, flaring opening, more so in the larger specimens. The largest is 30 cm high and 18 cm in width.

Neopetrosia eurystomata on sandy rubble at adepth of 108 m off the coast of Kralendijk Pier on Bonaire. Van Soest et al. (2014).

See also…

Calcifying Endosymbiotic Bacteria in a Non-Sclerosponge.

Sponges (Porifera) are generally considered to be the oldest extant animal group, with a fossil record that extends considerably into the Precambrian; phylogenomic analysis suggests they are the sister group to all other animals, which also suggests an early origin for the group.

Two new species of Chalinid Dermosponge from Western Australia.

Chalinid Dermosponges are among the hardest Sponges to classify taxonomically due to their simple anatomies and variable morphologies. They are encrusting Sponges with skeletons made up of...

Two new species of Theonellid Sponge from the Great Barrier Reef.

Theonellid Sponges are predominantly deepwater Sponges found across the globe, with a rigid skeleton made up of interlocking silica spicules. They are noted for the production of an array of unusual chemicals, the majority of which are thought to be produced by...

 

 

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