Wednesday, August 5, 2009

BREAM researcher Jessie Hallett in the Mid Ocean on July 31st

Mid Ocean News link here


Published: July 31. 2009 12:00AM
How our wetlands have shrunk over past 200 years


By Alex Scrymgeour

BERMUDA has lost 57 per cent of its wetland areas in the last 200 years. With continued coastal development and people continuing to dump trash illegally at marshes and other wetland environments the problem is only getting worse.


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Last night, Jessie Hallett, a researcher with the Bermuda Zoological Society (BZS), gave a lecture in the main hall of the Bermuda Aquarium Museum and Zoo (BAMZ), discussing how marine and wetland habitats of Bermuda have changed in the past two centuries.

By comparing a 200-year-old detailed map of our reef and wetland areas to those of today she showed the impact on Bermuda's fragile environment.

Speaking with the Mid-Ocean News earlier, Ms Hallett and Dr. Thad Murdoch, head of the Bermuda Reef Ecosystem Assessment and Mapping Programme (BREAM) at BZS, talked about the upcoming informative talk and the changes to Bermuda's marine and wetland ecosystem in the last 200 years.

BREAM maps the marine habitats of Bermuda and they have successfully mapped all the reefs and sea grass beds. Aerial photos were taken from planes and put into one big composite image. They then mapped the reefs and other marine environments using Geographic Information Systems (GIS) along with the photos.

Ms Hallett is comparing today's mapped reefs and wetlands to a map created 200 years ago by Thomas Hurd. From 1789 to 1797 Mr. Hurd detailed all of Bermuda's known reefs and wetlands.

"Jessie's project was funded by BZS," said Dr. Murdoch.

"The Hurd map was provided by Dr. Ed Harris of the Bermuda Maritime Museum in digital format. Thomas Hurd took eight years to map Bermuda's reefs and he used a water glass to do the mapping which made his map extremely detailed and accurate.

"It was Jessie's idea to compare the old map to the new aerial photos. Using those she compared what factors influenced change to the environment. Factors such as social or cultural play a big part in the change. The question then becomes: how can we use the knowledge to better conserve today?"

Ms Hallett also looked at the wetlands to see how they had changed. According to her research they have been dramatically changed with a staggering 57 per cent loss to the environment.

"Hurd's map had 46 wetlands and today there are only nine original ones left," stressed Ms Hallett.

"There are a couple of other ones that weren't on the Hurd map. They are thought to have have been ponds and marshlands.

"Paget Marsh is now a marsh that would have looked the same as it did in the 1600s. The restoration recently undertaken to the marsh did a great job restoring it. Anywhere flat in Bermuda was marsh before people arrived. The area adjacent to wetlands was very fertile and there were lots of farms there.

"Before proper waste disposal was introduced to Bermuda people would dump their trash in the marsh's around the island. Morgan's point American naval base would dump their trash in the marsh's as well."

The marine environment has gone through some dramatic changes of its own. North Rock is just a beacon for ships now, but 200 years ago it was an island.

Over the course of time people stationed at forts, and more recently the US Naval Air Station, would arial bomb and fire on reefs and North Rock for target practice.

"As far as the entire reef platform around Bermuda there haven't been a lot of changes except for human intervention," explained Ms Hallett.

"Clearing the ship channels did a lot of damage to the reef and we still have pollution and chemical problems.

"A lot of reefs were destroyed in ship channel creation because they didn't have the technology to make better choices. The western channels destroyed 40 hectares of reef versus the eastern Town Cut which destroyed less than a hectare of reef and land combined.

"If they ever fix up the ship channels the best option is to re-dredge St. George's Town Cut for new ship channels. Re-dredging will have far less impact to the already fragile marine environment than creating new channels elsewhere. The big issue in the west at Dockyard right now is the ships can barely fit through the existing channels."

In recent years coral and reef systems around the globe have been disappearing at an alarming rate.

Thankfully, as of right now, Bermuda has been spared the disastrous demise and we could soon be the worlds leading dive destination as our reefs are extremely healthy.

"Our reefs are thriving," said Dr. Murdoch.

"We still have parrot fish, which most places around the planet no longer have. They are protected in Bermuda.

"Also: No spear guns and no fish pots equals good for reefs. Our coral cover is great. However in contrast our grouper populations aren't great. We've wiped out our Nassau grouper population for good and our black grouper is slowly making a comeback.

"The data recovered is saying everything that can be eaten by a grouper and shark is thriving because there are no sharks or grouper left in Bermuda to eat them.

"The rest of Caribbean has taken a real hit in recent years with their reefs. In the last 30 years they have been decimated. Overfishing, bleaching from global warming, and disease have all led to their demise."

There are some simple steps people across Bermuda can take to help preserve our island environment.

With pollution and illegal dumping still at an all-time high Dr. Murdoch and Ms Hallett urge people to dispose of their trash properly.

They say conservation bodies such as Bermuda National Trust and Conservation Services are doing a great job at helping to conserve the environments and note the public has to do their part and act responsibly.

"Pollution is a huge factor to the destruction of any environment," cautioned Ms Hallett.

"The cultural thing of throwing garbage in the wetlands is still here in Bermuda even though the wetlands are improving.

"With all the costal development we should put more mangrove forests in. They are essential shelters for juvenile fish like snapper. They also protect our coast line from flooding. For the reefs the biggest threat is development, over fishing and pollution such as heavy metals from boatyards.

"Environmental impact assessment should be the first step in development of any project here in Bermuda. People need to be made more aware through education. Education is a huge factor in combatting environmental deterioration.

"With historical and eco knowledge, and new technology, we should be able to manage our environment. With all that knowledge we can protect our marine environment and protect our home."

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