Friday, December 23, 2016

12 Creatures on Buccoo Reef to cherish all year round

In observance of the season of celebration and thanksgiving, Jahson Alemu shares 12 creatures special to Buccoo Reef that we should cherish and protect. Make a note for 2017 to appreciate the marine environment that surrounds Trinidad and Tobago. Without it, we are rocks in the ocean, black dots on the map.  Follow Jahson on twitter: jahson_alemu

Christmas is in the air. The smell of pastelles, black cake, ham and all sorts of seasonal goodies tantalise our taste buds. From simple to intricate lights adorn houses; and like moths drawn to a flame, paranderos flitter from house to house to spread joy, serenade and wish us well for the season. In the spirit of the season, here is a Christmas tribute to some of the creatures that add vibrancy, wonder, colour and life to our Buccoo Reef.

Red Cushion Starfish, photo courtesy Jahson Alemu

On the first day of Christmas,
My true love gave to me,
One Red Cushion Starfish (Oreaster reticulatus).


Two French Angelfish, photo courtesy Jahson Alemu

On the second day of Christmas,
My true love gave to me,
Two French Angelfish (Pomacanthus paru), and
One Red Cushion Starfish



Three bottlenose dolphins, photo courtesy Jahson Alemu
On the third day of Christmas
My true love gave to me,
Three Bottlenose Dolphins (Tursiops truncates),
Two French Angelfish, and
One Red Cushion Starfish.


Christmas Tree Worm, photo courtesy Jahson Alemu
On the fourth day of Christmas
My true love gave to me
One Christmas Tree Worm (Spirobranchus giganteus)
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish


Batwing crab, photo courtesy Jahson Alemu
On the fifth day of Christmas
My true love gave to me
One Batwing Crab (Carpilius corallines),
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angel Fish, and
One Red Cushion Starfish


Black Grouper, photo courtesy Jahson Alemu
On the sixth day of Christmas
My true love gave to me
One Black Grouper (Mycteroperca bonaci)
One Batwing Crab
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish.


Brain coral, photo courtesy Jahson Alemu
On the seventh day of Christmas
My true love gave to me
One giant Brain coral (Colpohyllia natans)
One Black Grouper
One Batwing Crab
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish


Rainbow Parrotfish, photo courtesy Paul Asman and Jill Lenoble
On the eight day of Christmas
My true love gave to me
One Rainbow Parrotfish (Scarus guacamaia),
One giant Boulder Brain….coral
One Black Grouper
One Batwing Crab
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish.


Long-spined sea urchin, photo courtesy Jahson Alemu
On the ninth day of Christmas
My true love gave to me
One long-spined sea urchin (Diadema antillarum)
One Rainbow Parrotfish,
One giant Boulder Brain ... coral
One black grouper
One Batwing Crab
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish.


Queen Angelfish, photo courtesy Laszlo Ilyes
On the tenth day of Christmas
My true love gave to me
One Queen Angelfish (Holacanthus ciliaris)
One long-spined sea urchin
One Rainbow Parrotfish,
One giant Boulder Brain….coral
One black grouper
One Batwing Crab,
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish.


Spotted eagle ray, photo courtesy Laszlo Ilyes

 On the eleventh day of Christmas
My true love gave to me:
One Spotted Eagle Ray (Aetobatus narinari)
One Queen Angelfish
One long-spined sea urchin
One Rainbow Parrotfish,
One giant Boulder Brain….coral
One black grouper
One Batwing Crab,
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish.



Buccoo Coral Reef, photo courtesy Jahson Alemu


On the twelfth day of Christmas
My true love gave to me: a healthy coral ecosystem with
One health coral reef
One Spotted Eagle Ray
One Queen Angelfish
One long-spined sea urchin
One Rainbow Parrotfish,
One giant Boulder Brain….coral
One black grouper
One Batwing Crab,
One Christmas Tree Worm
Three Bottlenose Dolphins
Two French Angelfish, and
One Red Cushion Starfish.


Merry Christmas and Happy New Year!

Thursday, December 15, 2016

Forests on the Edge

Jahson Alemu, marine biologist, discusses the importance of mangrove ecosystems to the enhancement and protection of coastlines, and also to our future. This feature was first published in the Tobago Newsday on Thursday December 15, 2016
Follow Jahson on twitter: @jahson_alemu.

If trees are the lungs of the earth, mangroves must be the kidneys. Like botanical amphibians, mangroves live life on the edge. Uniquely positioned at the dynamic interface between land and sea, they are highly productive tropical coastal ecosystems comprised mainly of trees and shrubs capable of thriving in humid heat, amid choking mud and salt levels in which only a few plant species can survive (Duke et al 1998). If you’ve never seen a mangrove, picture a lattice of tangled tree legs rising up from brackish water. At one point in our history, mangrove forests were treated as wasteland considered only useful as dumps, and haven to bad spirits, jumbies, runaways and criminals.

Red mangroves (Rhizophora mangle) and intertwining prop roots in Bon Accord Lagoon. Photo by Jahson Alemu I, 2014
The mangrove swamp was avoided and condemned as breeding ground for disease, mosquitoes, frogs, snakes and other beasties the mind could imagine. At the same time, however, they were important sources of building material, firewood, medicine, food security (agriculture), homes for the poor, recreation and harbours for small boats. Today, mangroves have taken on additional meanings in our lives, where as well as the traditional roles, they now act as sources of revenue through ecotourism; major agents of soil stabilisation, coastal expansion and erosion control where interlocking roots stop land-based sediments from coursing out to sea. They build land, and their trunks and branches serve as barriers that diminish the erosive power of waves; and a climate regulators they store vast amounts of carbon that would otherwise be released into the atmosphere.

As discussed in last week’s article, they provide the unique requirements to create bioluminescent bays. But, probably one of the most well known roles of mangroves is as a home to wildlife (e.g. Scarlet Ibis) and nursery to fish and shellfish (e.g. spiny lobsters, snappers, tarpon and grouper). Altogether, these ecosystem goods and services have been valued globally at approximately US$32 billion annually, which translates to approximately US$194,000 ha-1 yr-1(Costanza et al 2014).

Despite their importance, our mangrove forests continue to be threatened and are rapidly declining. Significant alterations to mangrove forests in Trinidad and Tobago since the early 1970s have already resulted in an estimated 20% loss of mangrove forests due mainly to population growth and increasing development in coastal areas. Several examples illustrate these threats including decades of continued modification, built development encroachment: squatting and agriculture in the Caroni Swamp; the phenomenal shrinkage of the Friendship and Kilgwyn Swamps following necessary mangrove clearing for the Crown Point Airport runway expansion (IMA 1990); and development of the Canoe Bay Resort in 1980. Similarly, proposed resort and housing developments threaten the integrity of the Buccoo Bay mangrove forest. While there is growing recognition of the importance of mangrove forests, to date we have only managed to offer limited protection to three mangroves systems: Caroni Swamp, Nariva Swamp and Bon Accord Lagoon.

Coastal flooding and increased coastal erosion are but two of the major impacts we expect over the next 50-100 years if mangroves continue to shrink. In a recent review, the Institute of Marine Affairs described the state of mangrove conservation in Trinidad and Tobago as greatly challenged because of inadequacies in existing laws and institutional arrangements. If there is to be any meaningful slowing of the current rate of mangrove degradation and loss, an Integrated Coastal Zone Management (ICZM) approach is recommended as a means to promote coordination and clear distribution of responsibilities among the various authorities with jurisdiction over mangrove management.
The national bird, Scarlet Ibis (Eudocimus ruber), spends most of its life feeding and nesting in mangrove forests. Photo courtesy Charles J Sharp, 2014

 In spite of all these challenges, our environmental consciousness has increased tremendously over the last decade, and so too has our understanding of the role of mangroves in an uncertain future. Mangroves represent real opportunities for livelihood development (such as ecotourism, education, management); food security through the maintenance of juvenile fisheries stocks, biodiversity conservation especially of endangered species (e.g. goliath grouper/jewfish). In small islands such as ours, we are extremely vulnerable to climate change impacts, as such mangroves also represent important ecosystems for climate regulation and coastal resilience. Any development in or around these ecosystems should strive to have minimal impact on the mangrove forests, allowing them to thrive in their special relationship between the shore and sea.


References:
Costanza R, de Groot R, Sutton P, van der Ploeg S, Anderson SJ, Kubiszewski I, et al. (2014) Changes in the global value of ecosystem services. Glob Environ Chang. 26: 152–158
Duke NC., Ball MC and Ellison JC (1998). Factors Influencing Biodiversity and Distributional Gradients in Mangroves. Glob. Ecol. Biogeogr. Lett. 7, 27  1996,
IMA (1990) Environmental Impact Assessment of the extension of Crown Point Airport Runway, Tobago. 123pp
Juman R and Ramsewak D (2013). Status of Mangrove Forests in Trinidad and Tobago, West Indies. Caribbean Journal of Science, 47(2-3), 291-304.
Juman R and Hassanali K (2013) Mangrove Conservation in Trinidad and Tobago, West Indies (pp. 35-64) in (eds) Gleason G and Victor TR (2013). Mangrove ecosystems: biogeography, genetic diversity and conservation strategies. Environmental research.




Thursday, December 8, 2016

Lights in the Lagoon



Jahson Alemu discusses the phenomenon known as bioluminescence, and conditions where it thrives: the protected Bon Accord Lagoon in Tobago is one of these rare spots.. Jahson is a marine biologist completing his PhD study on Buccoo Reef and its value in the ecosystem of south-west Tobago. This feature was first published in Tobago Newsday on Thursday, December 8, 2016
Follow Jahson on twitter: @jahson_alemu.

Imagine a world without light!
That may seem difficult to imagine and it is likely you don’t think about it often! But for several animals part of their lives are spent in absolute darkness (such as at night or in the deep sea), and as such, they have evolved to cope with life in darkness by producing their own light, much like fireflies. This ability is called bioluminescence and simply put, it is the production of light due to an internal chemical reaction. More technically, it is the light energy produced as a result of the interaction of the compound luciferin with oxygen catalysed by the enzyme luciferase. Regardless, bioluminescence allows organisms to produce their own light, which we see as glowing in the dark, and the darker it is, the more intense the glow. This ability is used quite often in the marine environment by several species to attract prey (e.g. anglerfish), scare away or confuse predators (e.g. plankton), to attract mates (e.g. lanternfish), and even to communicate (e.g. plankton and squid). Interestingly, dinoflagellates (tiny unicellular bioluminescent marine plankton), are the most commonly seen example of bioluminescence.

I’ll never forget the excitement I felt when I first saw bioluminescence as the ocean shimmered in fleeting sparkles of green around Gasparee Island. I would have the same feeling several years later while on a night dive in Tobago, where as I descended to 100ft, with every motion, ghostly threads of green and yellow trailed behind me. But it wouldn’t be until 2014 while on a bioluminescence tour with Radical Sports in the Bon Accord Lagoon that I would be awed by the cinema of living light.

The Bon Accord Lagoon, Tobago, is one of those rare places (called biobays) where conditions are right for bioluminescence. Photo courtesy Islands of Trinidad and Tobago

There was no moon and it got darker as we paddled into the lagoon. But with every stroke our bows and paddles would glow. This was no gimmick, this was bioluminescence. Pretty soon we were seeing glowing fish darting about, and the bubbles they left also glowed which showed us where they came from. There was even a ray. Nothing moving in the water was hidden. The cause of this were bioluminescent dinoflagellate plankton (unicellular algae of the kingdom Protista). These microorganisms are autotrophic and produce their own energy through photosynthesis. What is most unique about them is that they use part of this energy to emit a bright flash of light whenever they are disturbed. The lagoon is rich with plankton, at concentrations high enough to produce this effect and as such is described as a biobay (bioluminescent bay).


Swim in light! Photo courtesy Radical Sports Tobago

Biobays are rare ecosystems that occur when microscopic organisms called dinoflagellates thrive in numbers large enough (and under the right conditions) to produce a glow-in-the-dark effect when they are stirred to action such as, by a fish or paddle. And when they glow, so does anything that comes in contact with them. As our paddles entered the water, the agitation excited the plankton, and flashed blue-green from our bows and paddles with every stroke. Scientist believe that the flash is meant to simultaneously attract a predator and to surprise the cause of the disturbance, with the result being a decreased likelihood of the dinoflagellate being eaten. 

Squid with small light organs on the underside of its body for camouflage. It uses this illumination to blend in with the sky, hiding its silhouette from predators watching from below. Photo courtesy Steve Haddock/Monterey Bay Aquarium Research Institute


The Bon Accord Lagoon is a protected inlet in Tobago’s protected marine park that holds millions of marine bioluminescent dinoflagellate plankton. The brackish water in this bay (a mix of salt water from the Caribbean and fresh water), combined with nutrients from decaying red mangrove trees (source of vitamin B12 required for dinoflagellate growth) make the area a perfect environment for bioluminescent dinoflagellates to thrive. Because the biobays require such exact conditions in order to form, there are very few in the world, and conservationists work tirelessly to preserve these unique phenomena. Arguably, Petit Trou in Tobago and parts of the Nariva Swamp support similar conditions to support biobays. The single most harmful species to these dinoflagellates are humans.

Current threats to these ecosystems include climate change and land based sources of pollution. Average ocean temperatures have steadily increased around Tobago over the last 15 years, and this rise would be even great for shallow ocean systems such as a lagoon. While plankton are adaptable, it is likely that a critical temperature threshold will be reached beyond which these plankton will not be able to survive. Additionally, waste (particulate or chemical) entering the lagoon can also affect the survival of these organisms; as the dinoflagellates are very sensitive to chemical pollutants such as heavy metals, industrial waste and sewage runoff (Lapota et al., 1993, 2007). Finally, an increase in light pollution in the area can reduce the observance of this phenomenon. 

Ultimately, the maintenance of this unique ecosystem may lie in our ability to protect and conserve our mangrove forest, which support the bioluminescent dinoflagellates and aid in cleaning land-based wastewater that enters the lagoon.


Jahson Alemu Photo by Mark Pierre


References:
Lapota, D., A.R. Osorio, C. Liao, and B. Bjorndal. "The use of bioluminescent dinoflagellates as an environmental risk-assessment tool." Marine Pollution Bulletin 54:12 (December 2007): 1857-67. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/17928009

Lapota, D., G.J. Moskowitz, D.E. Rosenberger, and J. Grovhoug. "The use of stimulable bioluminescence from marine dinoflagellates as a means of detecting toxicity in the marine environment." Naval Command Control and Ocean Surveillance Center (NCCOSC), Naval Facilities Engineering Command, 93-12127. 1993.

Thursday, December 1, 2016

Islands in the Orinoco

To the east of Trinidad and Tobago is the Atlantic, on the west the Caribbean Sea. However, the most powerful influence of water on these islands might be the fresh waters coming off the South American mainland. This week, Anjani Ganase, marine biologist, looks at the mighty Orinoco river whose delta comprises islands many times the size of Trinidad. This feature was first published in the Tobago Newsday on Thursday, December 1, 2016
Follow Anjani Ganase on twitter: @AnjGanase

“When Columbus sailed into the Gulf of Paria he had to make sense of two anomalies. His navigational readings were picking up the earth’s equatorial bulge, and the Orinoco being in spate meant that the water was fresh. Captivated by the apparently friendly natives, the exuberant vegetation, the benign climate and the extraordinary landscape, he called the area Tierra de Gracia (Graceland).”
-John Stollmeyer, Place of Beginnings, the World Views of the Amerindians of Cairi and of Medieval Europe, 2003

Columbus sailed through the Gulf of Paria on 1st August 1498, during his third voyage. It was this occasion that Trinidad and Tobago also marked as our “discovery day” commemorated in Moruga by mock landings of Columbus’ caravels, even though it is commonly thought that Columbus never came ashore.

In August, at the height of the rainy season, the Gulf of Paria would have seemed to the explorer a land-locked lake of fresh (sweet) water. Columbus didn’t stay in the Gulf of Paria but sailed south to the Orinoco delta, the region now called Amacuro, some 40,000 sq km of swampy forested islands.

Almost a hundred years later, Sir Walter Raleigh wrote of his 1595 voyage: “…the great river of Orenoque or Baraquan hath nine branches which fall out on the north side of his main mouth; on the south side it hath seven other fallings into the sea … but the islands are very great, many of them as big as the Isle of Wight… “ He also noted, “between May and September the river of Orenoque riseth 30 foot upright, and then are those islands overflowen 20 foot high above the level of the ground.”

Travel at any time of the year in the delta was necessarily by boat, and Raleigh wrote, “… these people that dwell upon the branches of the Orenoque, called Capuri and Macureo, are for the most part carpenters of canoes, for they make the most and fairest canoes and sell them in Guiana for gold, and into Trinidad for tabacco.”
 
Warao children paddle in the Orinoco delta. Photo courtesy Marc de Verteuil who leads tours up the Orinoco from Trinidad.

Raleigh persevered upriver and “beheld that wonderful breach of waters … more than 20 miles away, and there appeared some ten or twelve overfals in sight, everyone as high over the other as a church-tower, which fell with that fury, that the rebound of water made it seem as if it had been all covered over with a great shower of rain.” One of these mighty waterfalls would have been Angel Falls, the highest in the world. (Angel Falls tumbles off Rio Kerepacupai Meru which flows into a tributary of the Carrao River, itself a tributary of the Orinoco.)

Trinidad and Tobago sits on the continental shelf of South America. Trinidad is 12 kilometres from Venezuela, and Tobago 30 kilometres from Trinidad. Both islands are geological extensions of the mainland. Trinidad’s Northern Range and Tobago’s Main Ridge may be the easternmost extensions of a cordillera of the Andes. It is thought that Trinidad was separated about 11-15,000 years ago. The flora and fauna of our islands are identical to South American populations. A couple species that remain specific to the Orinoco are the pink river dolphin and the endangered Orinoco crocodile (the largartos of Raleigh’s description) which can grow to twenty feet.

The name Orinoco came from Guarauno words meaning “a place to paddle,” a place for transportation or navigation by canoes. It is also uniquely connected to the Amazon by the Casiquiare canal, a hydrographic divide between the Orinoco Basin and the Amazon Basin. The Orinoco flows west–north–northeast into the Caribbean; the Amazon flows east into the western Atlantic in the northeast of Brazil. The Casiquaire is a west-flowing section of Venezuela's Orinoco River with an outflow into the Amazon Basin.

Boat building in the Orinoco delta. 
Photo courtesy Marc de Verteuil who takes tours up the Orinoco from Trinidad.

The Orinoco basin covers an area of approximately 950,000 km2. It is bordered by the Andes to the west and north, the Guyana Highlands to the east, and the Amazon watershed to the south. The river, approximately 2,200 km in length, runs in an arc and its basin occupies an area that is most of Venezuela and part of Colombia.

The Orinoco delta, a region called Amarcuro, is a wide triangle extending about 400 km along the Atlantic coast of Venezuela from Pedernales on the Gulf of Paria to Punta Barima on the Boca Grande. The river flows into the southern Caribbean Sea, its waters bathing Trinidad and Tobago.

The outflow of the Orinoco delta brings a tremendous torrent of freshwater during the rainy season (usually April to November). These outflows bring many terrestrial and freshwater species from South America to Trinidad. It is rich in nutrients, and because it is less dense than seawater, the fresh water remains at the surface. This plume of waters can be observed, in satellite images, emanating from the Orinoco delta enveloping Trinidad and Tobago, and swirling into the Caribbean Sea, as far north as Puerto Rico.
 
Obtained by remote sensing from space, images like this illustrate biological and physical oceanic phenomena. In this view, warm colours are high chlorophyll. (From the Goddard Earth Sciences Data and Information Services Centre NASA)
Orinoco waters are carried around Trinidad and Tobago by what is called the Guiana Current. Tobago is subjected to the full force of this current which divides at the southeast coast; one part flowing in a northeasterly direction, and the other passing between Trinidad and Tobago in a northwesterly direction.

How do we know the Orinoco is flowing past our islands? When you dive in Tobago waters and observe the ocean’s green tint, you are seeing increased chlorophyll concentrations in the fresh water coming off the South American mainland. As much as we might like to identify as Caribbean islands, our South American connection is unmistakable.

Thursday, November 24, 2016

Cuba's Jardines de la Reina


One of the more pristine coral ecosystems in the New World, the Jardines de la Reina, south of Cuba, was named by Christopher Columbus for Queen Isabella. This week, Anjani Ganase, marine biologist, wonders how the opening up of Cuban-US relations will affect the protected marine park that was once Fidel Castro’s favourite fishing ground. 
This feature was first published in the Tobago Newsday on Thursday, November 24, 2016
Follow Anjani on twitter @AnjGanase

Recent discussions between the USA and Cuba have begun to open up relations between the two countries. For the first time in over forty years, we consider the question how opening Cuba’s market might affect the rest of the Caribbean with respect to economic competition and trade deals. For others, there is concern that this dramatic shift in Cuba’s economy will impact its natural environment. Will Cuba be precipitated into the development faux pas experienced by the rest of the Caribbean? Or will Cuba, an observer over these years, be able to learn from everyone else’s mistakes, and be able to progress with future climates in mind? What might they now plan for the next 30 years, this island nation that was allowed to grow differently with long-term isolation.
The iconic Giant Grouper provides one of the most charismatic and important species for marine tourism in Jardines de La Reina National Park. Photo courtesy globalconservation.org

When I was younger, I saw Cuba as a place of exile, a place where political ideology was not the democratic norm. It seemed a place so uninviting because so many people were willing to jump on unstable boats and risk their lives for a different kind of life.  The US embargo in the 1960’s stalled Cuba’s “development,” while the rest of the Caribbean continued building infrastructure, taking on the role of the vacation destination for the US. This fork in the road for Cuba shifted development focus to other forms of economic growth, such as agriculture, but also investment in scientific research, especially in healthcare and conservation.  If there were one advantage to a long-term regime that is pro-science and discovery, it would be this scientific freedom to imagine, research and experiment, a luxury that is rare in the scientific world.



“The future of our country has to be necessarily a future of men of science,” – Fidel Castro 1960

However, this freedom was a trade-off. Where most universities worldwide are heavily supported by government and international institutions as well as have intense cross border collaborations, the embargo has greatly limited Cuban scientists. There is limited connectivity to on-going international research and few opportunities for collaborations, not to mention the difficulty in acquiring necessary equipment. On the other hand, the limited access to technology also made the science creative and inventive.



It is unknown whether the protection of large tracts of marine and terrestrial areas, rich in biodiversity, under Castro occurred through the country’s need or isolation; whether large virgin tracts are the result of being left out of the world market or because of Castro’s genuine love for nature. I confess a particular interest in the protected archipelago 50 km off the south coast of Cuba that is home to the renowned coral reef - Jardines de la Reina (The Queen’s Gardens). These coral gardens were named by Christopher Columbus to honour Queen Isabella.

 
Surveillance of the hundreds of cays and waterways of Jardines de la Reina requires an innovative and cost-effective human and technology-based solution. Photo courtesy globalconservation.org
The protected area is about 2000 km2, an area roughly seven times the size of Tobago. These were also Fidel Castro’s personal fishing grounds. Jardines de la Reina is considered to be one of the last remaining pristine reefs and one of the largest marine protected areas in the Caribbean. Since its declaration as a marine protected area in 1994, the park has been closed to fishing, except for lobster, and restricted use for diving and tour operations with an annual maximum quota of divers. Today, local ecologists team up with international conservation groups, such as Global Conservation, monitoring the health and protection of these coral reefs that is home to a high biodiversity of fish population that is on average of eight times greater than the rest of the Caribbean. Jardines de La Reina is teeming with top predators including grouper, snapper and hogfish, which are generally a targeted species in fisheries (Pina-Amargos et al. 2014). A high diversity and abundance of sharks can also be found in the park, a sight that is very rare elsewhere in the Caribbean today. 

Caribbean Reef Sharks are Critically Endangered and survive only in a few places on earth, one being Jardines de la Reina National Park. Photo courtesy globalconservation.org

Much of the work done by scientists at the University of Havana is focussed on the movement of fish species in relation to their different life stages; it is well understood that the fish could roam large distances in open water, and inhabit different habitats at different stages of development; areas where they may not be protected. Therefore it is crucial to understand when and where they are most vulnerable. Further west along the Cuban coastline is the Zapata swamp, a protected wetland and home to the endemic Cuban crocodile. This location and other surrounding wetlands are likely to house many of these juvenile predators as shown by other studies on coral reef –mangrove connectivity.

Unfortunately, the coral reefs were not immune to the yellow band disease in the 1980s that infected much of the Caribbean branching coral communities, or the loss of the sea urchin, a major grazer on Caribbean coral reefs. Cuban reefs do not reflect the high hard coral cover that was prevalent during the 1970s and 80s, however the remoteness of these reefs and the low impact of nutrients and runoff from land development may have prevented further degradation in the years after, leaving small areas of healthy coral cover. It will be interesting to know how the fish communities have changed in the marine parks over the last 20 plus years, since the protection was established.

As the USA and Cuba begin to open up relations, there are finally opportunities for scientific collaboration and access by the international scientific community. These doors will also give access to business opportunities and visitors on the ground, something that Cuba’s economy may benefit from. However, what is key is whether the government can balance opportunity without compromising conservation. For Cuban coral reefs, even with the best management, there will undoubtedly be some effects on the reefs as accommodations for development occur. Hopefully, Cuba will continue slow and cautious in the face of the rapidly changing world.

For more information:
http://www.nytimes.com/2015/07/14/science/crown-jewel-of-cubas-coral-reefs.html?_r=0

Roman, J., Kraska, J., (2016) Reboot Gitmo for U.S.-Cuba research diplomacy, vol 351, issue 6279


Pina-Amagós et al. (2014), Evidence for protection of targeted reef fish on the largest marine reserve in the Caribbean. PeerJ 2:e274

Thursday, November 17, 2016

Release the Kraken!


In the movie, Clash of the Titans, Zeus unleashes his ultimate weapon when he commands, “Release the Kraken!” What is this monster (pronounced krak-en)? This week, Anjani Ganase, marine biologist, tells us about the oceanic giant squid that has been invoked in other films such as Pirates of the Caribbean. Although none as immense as those described by fishermen of a thousand years ago have yet been seen, who can say what lies in the unexplored deep seas that encircle our world. 
This feature was first published in the Tobago Newsday on Thursday, November 17, 2016
Follow Anjani on twitter @AnjGanase


The Norse legend of the Kraken tells about the mythical sea creature that lived off the coasts of Norway and Greenland.  It is a giant squid that rises up from the deep to crush vessels and pull fishing boats to a watery grave. Some of these stories recounted since the 1200s were documented by the Danish naturalist, Bishop Erik Pontoppidan, as part of his written works on the natural history of Norway (1752-1753). In his tales of the marine environment, he included many accounts of encounters by fishermen with this sea monster, the Kraken. He tells of fisherman who would row far out to fish: out to sea, they would find waters teeming in fish at the surface; and in these locations, they knew that below lay the kraken. The fishermen would harvest as much fish as quickly as possible, and seemed to know that more fish in shallow water near the surface would indicate when it was time to move, for the kraken would be  making its way to the surface feasting on the schools of fish above it.

“… they find that the Kraken is raising himself near the surface and then it is not time for them to stay any longer; they immediately leave off, fishermen take to their oars and get way as fast as they can. When they have reached the usual depth of the place and find themselves out of danger, they lie upon their oars, and in a few minutes after they see this enormous monster come up to the surface of the water, he there shows himself sufficiently...” - Pontoppidan
Hetzel edition of 20000 thousand leagues under the sea. Jules Verne (Public Domain)

In his book, the descriptions of the Kraken by the fisherman closely resemble the giant sea squids except for the sheer size of the creature:

 “…though his whole body does not appear, which in all likelihood no human eye ever beheld, its beak or upper part, which seems to be in appearance about an English mile and a half circumference, looks at first like a number of small islands, surrounded with something that floats and fluctuates like seaweeds. Here and there, a larger rising is observed like sand banks, on which various kinds of small fishes are seen continually leaping about till they roll off into the water from the side of it; at last several bright points or horns appear, which grow thicker and thicker the higher they rise above the surface of the water and sometimes they stand up, as high and as large as the masts of middle sized vessels.”

Today, it is commonly accepted that the giant squid is the kraken that the fishermen described in Pontoppidan’s book. Most of the research is carried out on deceased specimens that have been stranded, from deep sea trawling, from the stomach content of their predators, and from other related species. They can be found in the deep waters of most oceans, feeding on other fish and squid. Their only predators include most famously the sperm whales, known to have bite marks from the giant squid. Other predators include the toothed whales, sharks and swordfish; and it now appears that these creatures are not the top predators of the sea as we imagined previously.

“This animal has another strange property, known by the experience of a great many old fishermen. They observed, that for some months the kraken or Krabben is continually eating and in other months he always voids excrements. During this evacuation the surface of the water is coloured with the excrement and appears quite thick and turbid. This muddiness is said to be so very agreeable to the smell or taste of other fishes, or to both, that they gather together from all parts to it, and keep for that purpose directly over the kraken; he then opens his arms, or horns, seizes and swallows his welcome guests and converts them after the due time by digestion, into a bait for other fish of the same kind.” - Pontoppidan

Today research on these so called sea monsters have slowly turned fiction into fact. The excrement that the fishermen describe may actually be the ink that squid releases, which is a thick mucous fluid composed of melanin. Often considered a smoke screen for a quick getaway from predators, the inky exudate darkens the water and blurs their vision. They can even emit an even thicker and darker cloud of mucus that retains its shape, resembling the squid itself, providing a decoy while the squid swims away. What the fishermen may have thought was a tactic for luring prey was more likely an attempt to make a quick getaway from other threats, including the fishermen themselves.
Giant Squid surfacing to feed on baited squid near the Ogasawara Islands, south of Tokyo, Photo by Tsunemi Kubodera, a researcher with Japan's National Science Museum

To date we still don’t know the global population of giant squids, and it has only been estimated by the sperm whales that feed on them. Not much is known about their hunting and feeding habits. They are considered to be strong swimmers and active hunters, even thought to have organs on their tentacles that emit light to lure in prey. Only one confirmed live encounter showed a giant squid feeding at 900 m depth on smaller squid; this was still some 1300m above the bottom. Their stomach contents also show that they do feed on crustaceans prevalent in the deep-sea bottom, indicating that they are capable of roaming at great depths. The age of these creatures is most uncertain; they are considered fast growing,  and many of the specimens caught might be merely teenagers. Finally, and most controversial of all, is the size of the giant squid. Old records suggest lengths of up to 60 m long, however there has never been any recent record of this. Recent studies have suggested a maximal length of 15m with most observed averaging about 11m; much different to the legends that speak of miles in length.

Ninety percent of our oceans are open-water environments remote from coastal environments. We know so little about the creatures that dwell there and much less about how we may be impacting them. Even these giant squids that are deep ocean dwellers aren’t immune from human activities. More strandings have been associated with exceptionally warm water, as well as from acoustic seismic soundings for petroleum. With the projections of warming waters, we can definitely expect more of these strandings to occur. The surfacing of giant squids may also be indicators of changing pelagic ecosystems under future climate scenarios– ocean acidification and warming temperature. Although they do not have calcium carbonate skeletons, their receptors for movement are calcium carbonate based and can be affected by lower pH levels. Warmer waters would limit the squids’ ability to extract oxygen out of the water column and could cause suffocation. With further science and growing education, it is hoped that we might also conserve these sea monsters of the past as living icons of the deep sea, symbols of ocean conservation and awareness.


References:
Roper, Clyde F. E. and Shea, Elizabeth K. 2013. Unanswered Questions About the Giant Squid Architeuthis (Architeuthidae) Illustrate Our Incomplete Knowledge of Coleoid Cephalopods*. American Malacological Bulletin, 31(1): 109-122.

Guerraa, A., Gonzáleza, A. F., Pascuala, S., Daweb, E. G. (2011). The giant squid Architeuthis: An emblematic invertebrate that can represent concern for the conservation of marine biodiversity. Biological Conservation 144(7):1989-1997

Pontoppidan, E. (1755) The Natural History of Norway



The following images were published in James B. Sweeney's A Pictorial History of Sea Monsters and other Dangerous Marine Life, 1972, Bonanza Books. The kraken are identified as giant squid, and alternately called octopus, calamari, or cuttlefish.







Thursday, November 10, 2016

The Caribbean War against Lionfish


This week, Anjani Ganase, marine biologist, tells us what we need to know about the presence of lionfish on Caribbean reefs. With no natural predators in the Atlantic, lionfish feed voraciously upon juvenile fish that are essential to healthy coral reefs. Introduced carelessly in Atlantic waters, man must take on the responsibility to stem the invasion.
This article was first published in the Tobago Newsday on Thursday, November 10, 2016.
Follow Anjani on twitter @AnjGanase
 
Lionfish in its native home, the Great Barrier Reef. Photo by Richard Vevers, The Ocean Agency, XL Catlin Seaview Survey 2012.
Lionfish Invasion
Naturally present in the Indo-Pacific tropical waters, the lionfish is a common ornamental fish in the aquarium trade. In the 1980s, two species of lionfish - red lionfish (Pterois volitans) and the devil firefish (Pterois miles) the less common of the two - were introduced into the marine waters along Florida’s east coast, a notorious “hotspot” for marine introductions. Lionfish is one of over 30 introduced marine species off the coast of Florida. By the 1990s they expanded their range farther along the east coast with sightings as far north as New York. Fifteen years later, in 2005, there were regular sightings in Bermuda and Bahamas and parts of the Gulf of Mexico. After this, the invasion of lionfish to the rest of the Caribbean accelerated. Lionfish continued to expand southward into the western Caribbean, invading the Greater Antilles, Cuba and Hispaniola, Belize and Mexico and parts of the Central America. By 2010, the invasion continued into the islands of the Netherlands Antilles west of Trinidad and Tobago, and the Lesser Antilles, St. Maarten and Guadeloupe to our northeast. By 2011, Barbados spotted their first lionfish so its southward track was inevitable, and Tobago had its first confirmed sighting in 2012. Although lionfish have invaded most of the Caribbean, experts don’t expect that they would be stopping here. Considering their environmental range, they predict that they will continue to spread further south along the coast of South America, to Guyana, French Guinea and eventually to Brazil inhibited only by colder waters. However, with warming climates they might even expand further.

Lionfish Strategy
In their native habitats, lionfish are uncommon and relatively unknown. On the Great Barrier Reef, an encounter with a lionfish was one to check off; but sighting these got old pretty quickly when they saturated your reef view. Lionfish are relatively rare in their native region in the Indo-Pacific; and they’re generally not considered a preferred meal because of their venomous spines. Adults are hardly considered prey, except by Cornetfish in the Indo-Pacific and Nassau Groupers in the Bahamas.

On the other hand, lionfish are incredible hunters. In one study that compared the hunting strategies and prey choices of lionfish in the native and introduced territories, they are generalist feeders, feeding typically on juvenile and small fish species. Their banded coloration helps them to blend in while hunting. They mostly hunt in low light, at dawn and dusk or overcast conditions, which is common for most predators including sharks. During daylight, they hide in cryptic environments such as under rocky crevices. They have two main strategies for hunting. They fan out their pectoral fins - similar to how batman fans out his cape before he descends on the bad-guys – to herd and corner small fish. Lionfish also have a blowing strategy where they propel water onto the prey to confuse and disorient them. Although it was found that the techniques and feeding times did not change much between the regions, it seems that the success rate is higher in the Caribbean because they are not perceived as a threat. In the Caribbean, they have been able to feed on larger fish. The blowing technique also seems to be unnecessary, as prey is more easily caught. Pacific fish species seem to be more aware of their presence.

The broad range of tolerance to different environments, occurring across significant temperature and depth ranges, has facilitated lionfish presence in the Caribbean. Lionfish can be found down to 100 m deep. They also mature quickly, have fast reproductive rates and long life spans.

Ecological Impacts
What lionfish feed on is the main cause for concern in the Caribbean. One group of fish – the parrotfish – are important grazers of macro-algae on Caribbean reefs and crucial in maintaining low cover of algae, which are the main competitors against hard corals for space.  Lionfish can feed heavily on the juvenile populations of these crucial herbivores; and on coral reefs where populations of parrotfish are already severely compromised the impacts can be disastrous for the health of our coral reefs. They also undermine the predator population by feeding on the already heavily depleted juvenile populations of groupers and snappers, reducing their recruitment levels on coral reefs, even as they compete with them for food.

What eats Lionfish
Island states have taken up the responsibility of hunting and killing lionfish in an effort to limit their populations at least within the diving limits in shallow coral reef environments. Special tools were made: a polespear and a canister were designed to kill lionfish safely while minimising damage to the reef and other marine life. The spears have to be used in close range with the lionfish. At this time, lionfish seem to be unaware of humans as a threat; but don’t miss, because they’re also quick learners. In the Bahamas and other countries throughout the Caribbean, lionfish tournaments have been organised in an attempt to cull their populations, while creating the opportunity to monitor lionfish size, numbers and distributions. Once enough are caught, the lionfish can be used in culinary competitions, and people can learn how to safely prep this fish for eating. There is a lionfish cookbook produced by REEF.org and is available on Amazon.


Invasive lionfish cruising in the daylight on the Belize Barrier Reef. How many can you see? Photo by XL Catlin Seaview Survey, Global Reef Record.

What can we do to restore balance in our marine ecosystems? The observations that Nassau Groupers were feeding on lionfish occurred within one of the best marine reserves in the Caribbean, where the grouper populations are in the top one percent compared to the rest of the Caribbean (Mumby et al. 2011). Unfortunately, groupers are delicious food fish for humans; and healthy grouper populations may be as unlikely as finding another readily available bio-control on lionfish.

Unless we drastically curb the high levels of overfishing occurring throughout the Caribbean by setting up marine protected areas and regulating fisheries, lionfish will continue to be a threat to our coral reefs. Properly managed marine protected areas offer the best solution to many of the problems of the marine environment, including a natural means of curbing lionfish. Protected coral reefs will be more resilient to ecological and human induced changes.

References:
Schofield , P. J., (2010), Update on geographic spread of invasive lionfishes (Pterois volitans [Linnaeus, 1758] and P. miles [Bennett, 1828]) in the Western North Atlantic Ocean, Caribbean Sea and Gulf of Mexico Aquatic Invasions (2010) Volume 5, Supplement 1: S117–S122
Mumby PJ, Harborne AR, Brumbaugh DR (2011) Grouper as a Natural Biocontrol of Invasive Lionfish. PLoS ONE 6(6): e21510. 

Cure, K. Benkwitt, C.E., Kindinger, T. L., Pickering, E. A., Pusack, T. J., McIlwain, J. L., Hixon, M. A. (2012) Comparative behavior of red lionfish Pterois volitans on native Pacific versus invaded Atlantic coral reefs, Marine Ecological Progress Series, Vol. 467: 181–192.
Morris, J.A., Jr., and P.E. Whitfield. 2009. Biology, Ecology, Control and Management of the Invasive Indo-Pacific Lionfish: An Updated Integrated Assessment. NOAA Technical Memorandum NOS NCCOS 99. 57 pp.