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

-

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 effects of geophysical and chemical factors such as temperature and nutrient concentrations on natural environments.

Gerardo (front) checks the data uploading into
the laptop computer from an water particle sensor (see below)
that Dave (back) has suspended below the boat.

Gerardo Toro-Farmer, a graduate student at the Univesity of South California at Los Angeles is working with BREAM as well as collegues at USC-LA and NASA to develop different in-situ (in place) and remote-sensed (by satellite) light measurements. He hopes to develop a reliable, low cost, and low effort way to be able to measure water clarity and suspended particulate load across Bermuda’s harbours and out across the coral reef lagoon to the deep sea around us.

An underwater sensor which uses lasers to
count and measure the size of particles in the sea.

Objectives
Optical measurements will be compared between in-place instruments and data collected by satellites, to study the effects of sediment resuspension events on the water column optical properties on coral reefs and seagrass beds. In this research Gerardo will address two questions:

Question 1: Can in-situ optical measurements be utilized to estimate resuspension and movement of bottom sediments from navigation channels?
Question 2: Can remotely sensed data be used to identify and quantify resuspended sediment plumes that are produced by ships traveling across the Bermuda reef lagoon in shipping channels

Anticipated Results
Gerardo expects to find a simple relationship between suspended sediment load and remotely-sensed reflectance in the red and infrared channels of NASA satellite imagery.

Stereoscopic imagery from satellites should clearly reveal vessels and their wake. This information combined with satellite mapping of suspended sediments will likely provide valuable information on the contribution of ship traffic to resuspension and associated redistribution of sediments in the lagoon.

False color images created with loggers light intensity measurements will probably show a gradient from lower light level values closer to the channels during periods of high ships traffic, to higher values (higher light intensity) far from the channels and during low traffic periods. This gradient will be also observed with satellite images.

NASA's AQUA satellite, which is used to assess water quality in Bermuda
and around the globe from outer space.

Comments

Post a Comment

Popular posts from this blog

Mapping Bermuda's Coral Reefs

-
Image
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 ...
Read more

BREAM?!? Why BREAM?

-
Image
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 ...
Read more

Reef Watch: Empowering citizens to monitor Bermuda's reefs and fishes

-
Image
Bermuda’s coral reefs are vital to the persistence of our economy and wellbeing. Living coral reefs act as a self-healing protective sea wall, blocking storm waves from destroying our fragile limestone shoreline and the coastal infrastructure we built along its edge. Our tourism industry relies on the beauty and charisma of our island; contributed substantially by the many recreational and aesthetic opportunities provided by the coral reefs around us. An economic evaluation of the lagoonal reef, which represents half of the entire reef system, found that $750,000,000 to $1,250,000,000 are contributed to Bermuda’s economy annually by the reefs of Bermuda. It is strongly in our interests to ensure that the coral reef system that protects and sustains our lives is itself protected from the extensive harm that can be caused by bad human behaviour such as overfishing, dredging, shipping traffic and the global environmental threats of climate change and ocean acidification. Creole w...
Read more