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Showing posts from May, 2008

Surveying Bermuda's Entire Coral Reef Platform

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Since 2004 BREAM has been carrying out the comprehensive assessment of coral reefs across the Bermuda Platform. Multiple transects are surveyed at each site so that the data can be analyzed using standard statistical techniques in order to address ecological hypotheses. Replicate sites have been surveyed across the lagoon, along the shallow rim which defines the edge of the platform, and at many 30-ft deep forereef sites. Over 100 sites have been assessed so far.

At each site a team of 3 to 6 divers assesses both the corals and other animals and plants living on the reef surface, as well as the many kinds of fish swimming over the reef. The data collected to date has been statistically analyzed and the findings are being written into a BZS report that describes the patterns observed in corals, algae and fish as well as implications for management and directions for future research.

Parameters assessed include the following.

•CORALS:
SpeciesLength on lineWidth (x & y)HeightSurface Ar…

Photo Friday

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White grunts schooling over a fire coral.

Bob Ballard makes the case for exploring the oceans

Quote: NASA explores space; NOAA explores the oceans

NASA budget for 1 year = NOAA budget for 1600 YEARS!!!

WHY ARE WE IGNORING THE OCEANS??!?!?!

Watch the video - more on this topic with a Bermuda angle in next post

http://www.ted.com/talks/view/id/264

Assessing functional groups of hard corals across Bermuda

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Project context
Coral reefs are degrading across the Caribbean, and yet all species of corals do not seem to be equally affected. Examination of the functional traits that promote the persistence of some species despite the demise of others is needed if we are to understand why reefs are in decline. Corals in Bermuda were classified into functional groups, according to the manner in which they exhibit the primary functional characterisitics of growth, reproduction and defense. Assessment across reefs located over the North Lagoon determined that species within each functional group of coral responded to environmental gradients in a similar, theoretically-predictable manner.

Objectives
To determine how functional characteristics of each coral species affects the assemblage structure of corals on reefs located across environmental gradients of stress and disturbance.Specific objectives include:
Determining critical traits to use for classifying corals into functional groupsAssessing coral …

Photo Friday

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A finger coral in a seagrass bed.
This is a new species record for Bermuda,
and so far we have only found it in one bay!
[click image to enlarge] (c) 2005 T. Murdoch

Why do we use a Geographic Information System?

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In a recent post we described how we manually converted a high-resolution aerial image mosaic of the Bermuda reef platform into a set of georeferenced polygons - creating a digital map of all the reefs around the island.

There are many benefits to having an electronic map instead of a paper map.

Identity
When each patch reef was added to the database, they were each assigned a number. This means every single patch reef in Bermuda now has a unique ID tag that can be used to name them.

In this section of the aerial image, abouto 1km wide,
you can see the ID number of each patch reef.

Having an ID number for every reef helps scientists and resource managers, as it gives another way to distinguish each reef.

Proximity Mapping
Wecan ask the GIS programme to select reefs within a certain distance of another mapped object. For instance, if we have a layer representing the Island, we can ask the programme to select and highlight all of the reefs that are within 1 nautical mile from shore. This then …

Monitoring the Water Quality of Bermuda’s Coral Reefs and Seagrass Beds with NASA Satellites and UW Sensors:

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Project context
When sand and mud get stirred up in the ocean by either ships or storms, it has a negative affect on the plants and animals that live there.The sand smother and grind into the surface of the plants and animals. Also when up in the water in thick clouds suspended sand blocks the light reaching the sea floor that the plants and animals need to grow or to see.In order to know how the organisms living in the water and on the sea floor are being affected by the amount of sand and other material is suspended in the water, scientists usually go out in boats and measure water clarity and the amount of suspended sediments in sea water. These measures through time are similar to underwater weather reports and tell scientists how healthy the ocean is through time and from place to place.However, new methods and instruments such as remote sensing using satellites, and aerial photography from air planes, have expanded the capacity for studying biological processes, as well as the ef…

"Damn it Jim, I am a Doctor, not a SCUBA Diver"

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Unlike Bones, who used to say silly things like this on the original Star Trek series way back in the dark ages, we on the BREAM team ARE SCUBA Divers (and some are doctors too) - AND we get to hang out with surgeons too (well, ok - surgeon fish). Like medical doctors we are also worried about diseases, temperatures and whether our patients are pale or icky-looking.

This BREAM scientist is counting fishes and recording her results on the yellow clip board.

The ecological health of a coral reef depends upon the condition of all the corals, fish, algae, sea urchins, gorgonians, sponges and other critters that live on it. When a reef is healthy the amount of algae is low, corals are abundant, and there are numerous predatory fish, as well as fish that eat algae (plants) and fish that eat water-borne plankton.

A healthy reef off South Shore.

When we survey a reef, we take measurements just like a doctor does. We count and measure the size of corals, sponges, sea urchins and fishes to see …

Pretty Picture Thursday

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A juvenile Blue Tang poses near a Brain Coral
[click photo to enlarge]


Seaweed blenny

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A well camouflaged seaweed blenny in a sponge.

BREAM?!? Why BREAM?

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One may wonder why we would choose to name ourselves after the Bermuda Bream, considering some of the other, less pleasant names we Bermudians call the fish.

Well, there was the pragmatic reason that "Bream" started with a B - so we could start our name with "Bermuda"...

However, another draw was that the Bermuda Bream is actually an endemic fish, meaning it is a species found in Bermuda and no where else. Yep - our bream are ours alone, at least according to Caldwell (1965), who first stated this assertion. It' species name is Diplodus bermudensis.

That said, there are sister species found across the Atlantic, including one in the Mediterranean called the White Bream (Diplodus sargus sargus) which looks remarkably like our guy. I took a photo of the specimen below in the Monaco Aquarium a few weeks ago.


There are also bream over in the US and Caribbean, and down to South America, but with the much nicer name of Silver Porgy.

Not surprisingly there is some controve…

Mapping Bermuda's Coral Reefs

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BREAM, as part of the Bermuda Biodiversity Project at BZS, has developed the most comprehensive maps of Bermuda's coral reefs and other marine habitats that exist. In this post we will describe how we mapped all of the 35,000 patch reefs in the North Lagoon of Bermuda.

Our goal was to create a Geographic Information System (GIS) of all the reefs found around Bermuda. A GIS is a computerized map that also contains information about each object mapped. Computerized maps are better than paper maps because once you put all the information you know into the program, you can then ask it to tell you new information which the program can calculate based on what you told it. Some questions you can ask a computerized mapping programme are listed at the bottom of this post.

Before we mapped the location of each reef into a GIS (also called a geo-referenced map database), we needed a set of images of the entire Bermuda reef platform. The BBP, with assistance from the Dept. of Conservation Ser…

Wonderous Whip Morays

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Studying Bermuda's Own Spotted Eagle RaysA BZS-supported graduate research project undertaken in 2006, 2007 and again this summer by Matt Ajemian, a student at the U. South Alabama, Marine Science Dept, and the Dauphin Island Sea Lab'sFisheries Lab
Project Context
The spotted eagle ray (Aetobatus narinari), locally known at the “Whip Moray”, is fairly abundant over seagrass beds and sand flats of Bermuda. The Government of Bermuda has expressed interest in placing spotted eagle rays on the Protected Species List – however insufficient information of their population status and ecology has prevented any such action. The urgency for A. narinari data has become critical as they are potential predators of conch and scallops, both of which are also undergoing restoration from overharvest in Bermuda. Rapid population increases of other rays in North America (Science journal pdf) demonstrate that rays can impact shellfisheries quickly - highlighting the need for understanding the ecolo…

What is Good for Grunts is Good for We Bies too!

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Great News! Yesterday, Elvin James, Minister of the Environment and Sport,announced the designation of a temporary No Fishing Area north of Fort St. Catherine for the 2nd year in a row. This protected area was created in order to protect a Blue-Striped Grunt spawning aggregation (SPAG) that has been heavily fished during previous years.

Blue-striped grunts play an important role in our marine environment, as they are predators of small crustaceans and other invertebrates. Grunts often spend the day in schools on coral reefs, and then go out to neighbouring sandy areas and seagrass beds to feed at night. Studies have shown that when the grunts return to their reef home in the day time they bring important nutrients back with them that aid in coral growth. In doing so grunts act as a means for nutrients to move between the two habitats and thus act to enhance the ecological resilence of coral reef ecosystems overall.

Fishing a spawning aggregation is the very definition of an unsustaina…