Tag Archives: pristine

Elkhorn and Staghorn Fields in Bonaire

Tales of coral reefs in decline seem to be omnipresent. Various ocean conservation websites list estimates like, “75% of the world’s coral reefs will die by 2050” (http://www.coralvita.co/). Snorkeling along a coral reef I cannot help but wonder if 5, 10 or 20 years down the road will this beauty still be here at all?

Species of Acropora corals, or branching corals, known as elkhorn and staghorn naturally form dense thickets of reef in relatively shallow waters offering home for numerous fish and marine invertebrate species. However in the 1980s and early 1990s whiteband disease took a huge toll. This disease is named for a band of white necrotic tissue that spreads from the base of the coral at a rate of 1cm per day. In the Florida Keys, 95% of Acropora corals disappeared.

Elkhorn coral degradation at Carysfort Reef (Located just east of where I worked in Key Largo, Florida) Photo Credit: Phil Dustan

When I was working in Key Largo, Florida, there was one particular location that allowed students a rare glimpse of a huge elkhorn coral colony. I remember telling students how incredible this coral was given the disease of the past. Students would crowd around for a glimpse of this beautiful coral. But in all of my teaching, I never imagined that someplace else in the Caribbean football fields worth of pristine elkhorn and staghorn coral still existed.

An immense elkhorn coral field in southern Bonaire

Last Sunday my mind was blown! Our snorkel trip near the southern end of Bonaire Island featured MAGNIFICENT elkhorn and staghorn corals.

This snorkel was not for the faint of heart. After an hour-long swim against the current we reached our first elkhorn, a small but healthy colony that reminded me of my favorite colony back in Key Largo. I dove down and snapped photo after photo, trying to capture the best lighting. When I paused to look up, our instructor was far ahead, unwavering in her push to swim further. And the further we went the more beautiful the reef became. More elkhorn than I could have imagined. When we paused to catch our breath I promptly declared this to be the most amazing snorkel of my life! Our instructor laughed at me and said we hadn’t even gotten to the best part.

The staghorn coral seemed to go on forever!

When we reached it I knew. It felt like being in the maze during the Triwizard Tournament in the 4th Harry Potter book, only all the walls were thick, dense, healthy staghorn coral. It was a pristine that I thought had been lost forever and I felt like I had gone back in time to a world when coral reefs flourished.

Fish hiding within the dense staghorn coral thicket.
An octopus hiding out in this boulder coral colony. Notice the rubble debris it has gathered for a garden.

Although disease, warming ocean temperatures, rising ocean acidity, hurricanes and pollution are constant threats to our coral reefs, it is good to know that there are still places of incredible beauty.



Assessing Seagrass

Looking at seagrass!
Looking at seagrass!

Seagrass is the only marine plant that produces flowers for reproduction. This is because they evolved from a group of terrestrial plants which adapted back to marine conditions about 100 million years ago after first migrating to land roughly 200 million years ago. And how are these flowers pollinated without underwater birds and bees?! it is the waves and water currents which carry seagrass pollen from one flower to another.

A type of eel grass: Enhalus acoroides
A type of eel grass: Enhalus acoroides

Seagrass is an important habitat for juvenile fishes before they grow up and swim out to the coral reef. Seagrass also filters water and produces oxygen. When I snorkel I often watch the small bubbles on the seagrass blades, which disperse into the water allowing fish to breath. Finally, seagrasses have true roots to anchor them to the ground and also hold the sediment to the ocean floor. Thus, without seagrass the clear and beautiful turquoise blue water of tropical oceans would be much darker and more murky from floating sediment.

We lay a 50m transect line and then estimate seagrass % coverage per square meter every 5m on the line.
We lay a 50m transect line and then estimate seagrass % coverage per square meter every 5m on the line.

With the help of my office teammates we recently completed surveys of all of the seagrass beds in Odiongan. Now just 16 more municipalities to go until the province of Romblon has a complete set of data for monitoring change in seagrass beds over time.

My seagrass and mangrove assessment team members.
Overlooking Odiongan, with my seagrass and mangrove assessment team members.
With certificates to prove their expertise in mangrove and seagrass species identification.
They now have certificates to prove their expertise in mangrove and seagrass species identification.

Having finished our first series of assessments, we are all experts in seagrass and mangrove species identification. This is a much more challenging task in the Philippines versus Key Largo, Florida: The Philippines has over 40 species of mangroves and about 16 species of seagrass compared to the 3 species of mangroves and 7 species of seagrass common to the Caribbean Sea.

Reference for more info: http://bioscience.oxfordjournals.org/content/62/1/56.full