Entries in #reef (4)


Meeting The Gentle  Giants

I have been in Caye Caulker for 3 months now and I had the opportunity to encounter numerous amazing creatures already. From the quiet nurse sharks, the curious stingrays, the shy turtles or even playful dolphins, every animal has its own behaviour and reacts differently to human presence.

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Seismic Testing in Belize 

Here in Belize there has been a campaign running in the last few years to ‘Say No to Offshore Drilling’, but unfortunately the government wasn't listening and this week on the 19th of October a company that conducts seismic testing had a ship enter Belize’s waters and begin testing.

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Caye Caulker Barrier Reef System 

Caye caulker has a three stage barrier reef system, a general use zone, a conservation zone and a preservation zone. This three stage idea was set up in 1998 in order to help preserve the marine life and corals; it does this by monitoring the amount of people who use the reef and banning fishing in the majority of places along the reef.

One of the biggest issues they have faced is people feeding the marine life. Some divers I have spoken too have said that they previously used to feed marine life such as Moray Eels, Ray's and Sharks until research showed that this had no benefits other than luring the animals closer. The downside to feeding the marine life is that they become so comfortable in approaching humans and boats as soon as they hear a boat engine they flock because they think they will be fed.

This makes poachers jobs incredibly easy but the animals very vulnerable. Although the fisheries department and FAMRACC have made extraction illegal in the conservation and preservation zones it cannot be monitored 24/7 so unfortunately some fisherman try to fish there illegally. This is not helped by the fact that many snorkelling and diving company's still feed the animals attracting them in for the fishermen. In fact, there’s only one company on the island that publicly discourage this and have a few signs outside telling people that they do. When I talked to a local about their views on this they loved that the shop was supporting not feeding the marine life. Although it could potentially affect their business they are only interested in attracting a certain clientele, people that are interested in the environmental aspects and the preservation of the reef.

Your rights as a diver are to appreciate the beauty of the ocean and preserve it, not contribute to its demise. It's very refreshing to be on a small island where the vast majority of people are so conscious to how their actions are effecting the environment.

By Maddie  Welsh - Marine Conservation Volunteer

Find out more about the Belize Marine Conservation & Diving project.

Check out what volunteers in Belize are up to right now!


Coral Bleaching 

To understand coral bleaching, one must first learn a little bit about the biology of corals. First of all, corals are not plants, and similarly they are not simply rock as many novel witnesses to a reef will believe.

They are in fact animals and while they do lay down calcium carbonate (or limestone) – which is responsible for forming the massive tropical marine structures referred to as reefs – they are actually more related to jelly fish than they are to plants. They are comfortably nestled in the Phylum Cnidarians – a taxa of invertebrates that are united by the following attributes; a life cycle with sessile (stationary) and medusa (free swimming) phases; radial symmetry; and the presence of a special type of ‘stinging’ cell called nematocysts (effectively a harpoon cell with a trigger hair and a venom sac). Hard and soft corals belong to the class Anthozoa which also includes anemones, sea pens and sea fans. One very interesting ecological adaptation of many species within Anthozoa is the mutualistic symbiotic relationship with microscopic algae known as Zooxanthellae.

healthy coralThe Zooxanthellae live in the surface tissues of the coral colonies. They are very adept at photosynthesis; that crucial biological phenomena, without which the vast majority of ecosystems on the planet wouldn’t exist. They produce far more glucose than they ever actually need to survive themselves – and this excess is gladly ‘mopped’ up by the coral. Many species of coral will supplement this diet by filter feeding, but most estimates suggest that 80% of the calorific intake for the colony comes from the sugars produced by the Zooxanthellae. All in all, the algae are crucial to the corals’ survival, and thus, the overall health of the reef ecosystem. Unfortunately it is a very fragile relationship that requires a more or less constant bio-chemical environment to function effectively.

Research now shows that under conditions of increased sea temperature the various rates of reaction for the necessary steps in photosynthesis increase. The amount of glucose produced increases, but this is not a good thing, because the higher rates of reaction reduce the stability of the whole system, and very destructive oxygen free radicals are produced. If left unchecked these free radicals have the potential to cause serious cellular damage within the coral tissues. To combat this, the coral effectively ejects the algae, and tries to make do with filter feeding to sustain itself. This is a tall order for any organism (although medically, I can think of a fair few cases where consuming 20% of the ‘natural’ diet might be a good thing?).

This is where the term bleaching comes from. The corals, without their photosynthetic algae turn a shade of ivory white and more serious cases can leave the whole reef looking like an ominously fragile skeleton. There are some species which turn other colours such as purple or pale yellow, but in essence without the natural pigments provided by the algae, the coral takes on a completely different appearance. This whole state is very taxing to the coral, and if elevated sea temperatures persist, then the reef slowly starts to die.

bleached coralAny given coral colony will hence have a natural temperature range in which its Zooxanthellae work most effectively. Coral bleaching will happen fairly innocuously in a healthy ecosystem and the coral colonies will often recover, but there are times when global climatic fluctuations spell real trouble. Twice in recent memory, first in 1998 and then again in 2010 there have been devastating world wide incidences of serious bleaching patterns, which have since been dubbed Global Bleaching Events (GBEs). Both of these years coincided with the global climatic fluctuation known as El Nino Southern Oscillation (ENSO).

During El Nino years the sea currents in the Pacific Ocean deviate from the stable norms, and a massive influx of unseasonably warm water drifts across from western South America all the way to the Indian Ocean. The effects are widespread and there are serious upsets to agriculture and fisheries all across the Southern Hemisphere. The El Nino events in the winter of 1997-1998 and early 2010, are widely considered as one of the main causes for the respective GBEs. Climatologists say we are now entering the first El Nino year since 2010 and as such face the third GBE within 17 years. The first GBE resulted in up to 70% coral mortality in some places, with the Maldives being particularly effected, but reefs in the Mediterranean, the Caribbean and the South Pacific also showing signs of significant degradation.

Here in Belize, the corals have started to show signs of bleaching. Colonies of two of the most dominant species here, known commonly as Lobed Star Coral and Massive Starlet Coral (or scientifically Orbicella annularis and Sideastrea sidera respectively) are exhibiting early signs of bleaching. Forecasts predict that coral mortality might result in the loss of more than 12,000 square kilometres, or 5% of all of the world’s coral. These numbers are staggeringly high, but paired with additionally stressors on the ecosystem such as overfishing, nutrient run off, coastal development and ocean acidification the future looks bleak for coral reefs. Yet as the past has shown, they are robust ecosystems and new evidence is really starting to show how resilient they are to these environmental perturbations.

Bleached coral stones washed up on a beachProjects like ours aim to monitor coral cover among other things, and help to paint a detailed picture on how healthy the reefs are and how they are effected by these problems. Only time will tell how badly effected our beloved reefs will be, but in the mean time it is definitely time to wake up and become aware and educated about the issues facing some of the most important, beautiful and essential natural resources on the planet.

By Rob MacFarlane - Principal Investigator

Find out more about the Belize Marine Conservation & Diving project.

Check out what volunteers in Belize are up to right now!