Tegan’s Science Notes #10 – Protecting Marine Biodiversity

This is the tenth in a series of “Science Notes” from from our ocean scientist colleague, Tegan Mortimer, who works with Earthwatch Institute. These postings follow from encounters with nature that I have on the water. Links to all her Science Notes can be on our Citizen-Science Resource Page. – DR

Tegan MortimerLike gigantic conveyor belts, the tropical oceans span the areas closer to the equator where water temperatures are over 75°. These warm and clear waters tend to have low levels of oxygen and nutrients, the opposite of the cold, nutrient rich waters I’ve written about in earlier Science Notes. This means that though tropical areas in general have low productivity, there are distinct ecosystems in tropical areas like coral reefs and mangroves that have very high productivity and are in fact, some of the most bio-diverse habitats on earth.

:: Coral Reefs: Gardens Under Siege


Despite the lack of nutrients and oxygen present in these warm waters, tropical areas play host to one of the most diverse ecosystems on earth: coral reefs.

Screen Shot 2014-05-30 at 11.59.50 AMA coral reef is made up of many colonies of coral polyps which build the reef structure out of calcium carbonate. Tropical corals contain zooxanthellae, which is tiny algae that lives inside the coral where it photosynthesizes, creating food from sunlight. These algae are also what gives coral its brilliant and diverse colors. This means that coral can only occur in the “photic” zone, where sunlight penetrates the water. Corals polyps feed by extending stinging tentacles outwards to capture small prey and particles in the water column. Corals are related to other stinging animals including sea anemones and jellyfish.

The complex physical structure of a coral reef, some of which are thousands of years old, creates an ideal habitat of many other animals to thrive – from small invertebrates to large animals like sea turtles and sharks. The productivity of many tropical marine areas as well as the related economic activities that center around fishing and tourism are highly dependent on the health of coral reefs.


In today’s changing ocean, coral reefs are under siege. Sea surface temperatures are increasing, atmospheric carbon dioxide is driving up ocean acidity, and overfishing is removing critical fish and invertebrate species at the same time that coastal land development is increasing in many coral reef areas. All of these pressures are contributing to the unprecedented and rapid collapse of coral reefs along with the loss of the unique ecosystem that goes with them. Scientists are racing to learn more about how these ecosystems are functioning under speedily changing conditions and how we might increase the resilience of corals, and help them cope better under a variety of different stressors.

Dr. Carrie Manfrino is an Earthwatch scientist studying just this area, but with an exciting twist called “coral gardening.” A great obstacle to coral resilience is that when large areas of corals disappear, it greatly reduces the ability of larvae to successfully settle in to form new baby corals in new areas. Staghorn and Elkhorn corals are branching corals which are a critical part of the coral ecosystem, but in the Caribbean these corals have decreased by as much as 90% in some areas, due to climate change and development pressures.


In the Cayman Islands, where Dr. Manfrino works, these corals are showing some very promising recovery, and her team is working to find out what characterizes sites where these corals are doing well. Once new sites are identified that match these characteristics, scientists and volunteers transfer baby corals that have been grown in a special coral “nursery” to these new sites. The idea behind this method is to both increase coral cover as well as to maintain islands of coral that are better connected with each other which help increase the production of new coral naturally. This is super exciting science, which is using a variety of new technologies to better understand and manage our impacts on the natural environment. (Here’s a video w/ Dr. Manfrino and her colleagues.)

:: Protecting Special Places

Just like anywhere on earth, special places need special protection. The unique biodiversities supported in tropical areas means that there are many special places in need of protection. This process is usually achieved through the creation of multi-nationally supported Marine Protected Areas or MPA. An MPA usually has one of two purposes, to protect an area that supports rare or important species, or to provide a refuge for animals from fishing. MPAs can vary in size from very small local protected areas to vast areas like those in the map below. The most important thing is that an MPA is large enough to matter and located in the right place so that it can provide the most benefit and achieve its purpose. The idea of designating marine areas to be protected is a relatively new one (2000) when compared to the creation of national parks, which started as early as 1872 with the creation of Yellowstone National Park in the U.S.

Currently just 1% of the ocean is fully protected.

So that the right places can be protected, scientists are studying how different animals use their habitat. It is important to be able to know what places are used for feeding, breeding, and resting so that these important functions can be maintained.

Screen Shot 2014-05-30 at 12.54.31 PM

On the Pacific coast of Costa Rica, in an area called Gulfo Dulche, Lenin Oviedo, an Earthwatch scientist, is conducting a research project to study how this pristine area is important to resident and migratory species of dolphins and whales. Bottlenose dolphins, Pantropical spotted dolphins, and humpback whales use this area either as their permanent home or as a way stop during larger migrations. Along with mapping how these different species use the gulf, the research team is interested in how boat traffic and boat noise overlaps with important whale and dolphin areas.

It is common that special places for animals are usually special places for humans too. Healthier ecosystems support the wildlife, which also benefits economic activities like fishing and tourism. It is important to understand how these activities impact the environment to see how they might be better managed.


Farther east in the Bahamas, Annabelle Brooks is another Earthwatch scientist whose research is in studying the spatial movements of juvenile green and hawksbill sea turtles. All species of sea turtle are endangered, so it is very important to protect areas, which are crucial for feeding. This research also allows the team to understand naturally occurring cycles of abundance and movement. As impacts from human activities and climate change become more widespread, this research allows scientists to spot disruptions, which are outside the naturally occurring changes in populations.

Researchers like Oviedo and Brooks use the power of computer modeling to better understand natural change and movement in populations. By combining observations of animals with data about the environment, they create a computer model that tells them which areas are important for specific animals or animal activities based on the environmental characteristics. Then the research team goes back into the field and collects more data which is used to validate the models, to see how good the models are at predicting observations in real life. This technique is very useful for pinpointing large areas that are important for specific animals. The aim of both these projects and many others like them is to better understand essential habitats for these important species so that we can better protect them in a changing ocean.

– Tegan Mortimer <teg.mortimerATgmailDOTcom>

Tegan’s Science Notes #3 – Sea Turtle Rescue

Explorer GuidesMost conservation efforts around the world are focused on protecting animals and their habitats in their natural conditions. Many of our Earthwatch Institute scientists study endangered species so that we can better understand their lives, their movements and how they interact with their environment. Such scientific efforts also help to inform lawmakers who can then move to protect important areas, ban hunting or harvesting of rare species or manage existing threats to animal populations.

I am very lucky to be involved in conservation action which takes a slightly different route to protecting endangered species: rescue and rehabilitation of sea turtles.

Sea Turtle Rescue
A green sea turtle getting an exam(source: rescue.neaq.org)

Every winter, turtles in New England run into trouble if they fail to migrate south to warmer waters. Sea turtles are superbly suited to life in the ocean, but as they are reptiles they don’t thermo-regulate. Instead they rely on the surrounding water to control their body temperature. If the temperature drops too low, the turtles can suffer from a form of hypothermia called “cold-stunning.”

Cape Cod Sea Turtle Rescue AreaWe usually associate sea turtles with warm tropical waters, but New England waters are important summer foraging areas for several varieties, including juvenile Kemp’s ridley, loggerhead, and green sea turtles. When the air temperature starts to drop, that’s a sign that the turtles need to start moving south; they’re usually long gone by October. But some turtles fail to migrate and end up incapacitated by the cold water. They float in the water unable to move and are pushed by wind and waves until they wash up on a beach. In Massachusetts, the highest concentration of these strandings occur along the beaches of Cape Cod Bay.

It’s not known why some turtles don’t head south. Some scientists believe that turtles that are spending time in shallow bays may be caught suddenly as the water can cool very quickly in these types of environments. Others think that turtles which enter Cape Cod Bay may be unable to navigate out of it as heading north to get around the tip of the cape is counter to their instincts. In any case, every year many turtles will strand on these beaches, though 2012 was a record-breaking year with over 240 turtles rescued off cold beaches.

The rescue operation starts with a team of very dedicated volunteers from Massachusetts Audubon’s Wellfleet Sanctuary, who carefully walk the beaches after every high tide whether that’s early in the morning, late at night or in bad weather. When the turtles wash ashore they are exposed to extremely cold air, so it is important to find these turtles as soon as possible. After a quick exam, the turtles are transported to the New England Aquarium Animal Health Center where veterinarians and rescue staff coax them back to life.

As the turtles slowly warm up they will be assessed for injuries, have blood drawn, have x-rays taken and be allowed to swim in shallow pools with supervision. Once they warm up, they will be moved to the big tanks to continue their recovery. Rehabilitation can take months as turtles can have injured flippers, pneumonia, eye injuries among other ailments which need medical attention. One turtle even received acupuncture!

Sea Turtle Rescue TanksTanks hold turtles until they are recovered enough to released – (rescue.neaq.org)

Once they are stable they may be transported to other facilities that will continue to care for the turtles until they can be released to the wild. Over 80% of the cold-stunned turtles which come to the New England Aquarium will make a full recovery and be released back into the wild. Some of these turtles will be fitted with satellite tags which will track them in their first months of freedom. This is helping scientists learn more about sea turtle navigation and movement.

Sea Turtle Rescue
Kemp’s ridley turtles being released – (rescue.neaq.org)

Why is this work important? The rescue team regularly rehabilitates three species of turtle: loggerheads, greens, and Kemp’s ridleys. All three of these are classified as “endangered” with decreasing populations. The Kemp’s ridley in particular is the most critically endangered species of sea turtle in the world; in the past 70 years, the population has gone from 89,000 nesting females to only around 1,000! Kemp’s ridley turtles have an interesting nesting ritual callled an “arabada” or mass nesting where the females will come on to the nesting beach all at once taking over whole sections of the beach. (See photo below.) This behavior makes them very susceptible to hunting, which has severely reduced their population. Today they are also threatened by habitat destruction, pollution and entanglement in fishing nets. There is a huge amount of conservation work being done to address these threats including fitting trawl nets with turtle exclusion devices (TEDs) and protecting nesting beaches. The work to save these turtles from certain death in Cape Cod Bay is just one part of the bigger work being done to save these species from extinction, and part of the much grander effort to preserve the diversity of life in the natural world, of which we are all a part.

Want to learn more about sea turtles?
• Follow the New England Aquarium Rescue team’s blog at rescue.neaq.org to learn more about cold-stunned sea turtles.
• Visit seaturtle.org which has lots of interesting information about sea turtles and sea turtle science.
• Take the hands-on approach and sign up for an Earthwatch expedition studying sea turtles.
• If you live in the Cape Cod or Long Island region volunteer as a beach walker or turtle transport driver.

Sea Turtle Rescue
An arabada, Spanish for “arrival” nesting event – (source: jameskaiser.com)

:: Tegan’s Earlier Science Notes:
#1 – Bird Migrations
#2 – Wind and Weather
:: Citizen Science Resources Page

:: BDX Explorer Guides
– Our Watery World
– Wind and Weather
– Math
– Sea Life
– Oceanography
– Sailboat Glossary
– Mentor Guide

Do you happen to know other scientists, educators or journalists who might be interested in our Learning & Discovery agenda? If so, we’d love to make their acquaintance. We can always be reached at oceanexplorer@bodaciousdreamexpeditions.comThank you!

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