Observing the Ocean

Perspectives | May 28, 2024

The ocean is a big, ever-changing system. Fish are constantly moving around and weather conditions can change in an instant. This makes studying marine ecosystems challenging, but scientists have some innovative tools at their disposal to make it easier.

Large yellow buoy in choppy ocean waters.

Looking out at the Gulf of Maine, it may seem daunting to figure out what’s going on beneath the surface. The water is dark, deep, and vast. There’s so much below the surface that we cannot easily see or measure, but people who live and work on the Gulf of Maine need information about the ocean that will help them in their day-to-day lives.

Fisheries managers need to know about fish population levels so they can protect species while also supporting local fishermen’s livelihoods. Fishermen and other mariners need to know when it is safe to go out on the water. Surfers want to know when the waves are right. Two important tools scientists can use to help answer these questions are environmental DNA (eDNA) and deep water buoys.

How can we study fish populations without casting a net?

Successfully managing fisheries in the Gulf of Maine means finding a balance between protecting vulnerable species and supporting the fishermen who rely on our coastal ecosystem. To do this, fisheries managers need to know what fish are in the water, where they are, and how abundant they are. Scientists have many tools to learn about fish populations, such as sampling fish in trawls or using technologies such as acoustics and telemetry. But these techniques can be time-intensive, costly, and sometimes impractical in hard-to-reach areas. GMRI research scientists are now looking to eDNA as another potential tool to study species distribution and abundance.

Environmental DNA (eDNA) is an exciting and promising new tool for “observing” and quantifying animal populations in a variety of environments.

What is eDNA?

As fish swim, they shed bits of scales and skin, leaving behind traces of DNA. Those traces of DNA that fish leave behind are what we refer to as eDNA. When GMRI Research Scientist Dr. Graham Sherwood ventures out at night aboard our research vessel, Merlin, he doesn't need an underwater camera or a fishing pole to learn what’s swimming beneath the boat. Instead, all he needs to do is collect a few liters of seawater.

From these bottles of water, Dr. Sherwood can tell how abundant a particular species is in the sample location. Researchers in his lab filter the water sample to extract the DNA. The amount of DNA collected on the filter paper is too small to study, so they use a technique called quantitative-PCR to amplify the small amount of DNA.

With each amplification cycle, the amount of DNA doubles, until eventually there is enough DNA to detect. The number of cycles it takes to reach this point tells them how much DNA they had at the start.

Studying fish populations through eDNA is an exciting new technique that could help scientists like Dr. Sherwood get a clear picture of fish populations when traditional techniques fall short. He and his team have been working on validating this process for several years now, and the results look promising.

There’s been really remarkable correspondence between what we were capturing in the trawl and what we were seeing from the eDNA. A big shift regarding eDNA was going from just being able to identify the presence or absence of a species, to actually being able to say something about the abundance of that species in the wild.

Graham Sherwood, Ph.D. Senior Scientist

Where eDNA could be most useful is in situations where traditional sampling techniques fail to tell an accurate story. Several years ago, fisheries managers saw a decrease in cusk populations and were looking to list cusk as an endangered or threatened species in the Gulf of Maine. However, local fishermen had observed an abundance of cusk near rock piles where trawls could not capture them.

An illustration of a cusk.

Our scientists worked with local fishermen to use cameras and line sampling and found that cusk were not actually dwindling — they just weren’t being caught by traditional sampling techniques. In the future, eDNA could be a simple and effective method of verifying species abundance to better answer these kinds of questions.

"From the point of view of fishing communities, it's always good to avoid unnecessarily strict management scenarios. Our use of eDNA could help greatly in that pursuit.

Graham Sherwood, Ph.D. Senior Scientist

eDNA is just one of the innovative new methods scientists are using to study the ocean. In addition to knowing about the presence and abundance of fish, it’s also important to understand how environmental conditions overall might be playing a role in changing the Gulf of Maine ecosystem.

That’s where “smart” buoys come in. Our Ocean Data Products (ODP) team, led by GMRI Senior Program Manager Riley Young-Morse, helps scientists identify climate patterns and weather conditions with the technologically advanced buoys that are part of the Northeastern Regional Association of Coastal Ocean Observing Systems (NERACOOS) network.

Using smart buoys to observe the ocean

Our ODP team works with seven deep water buoys that collect and transmit real-time data about ocean and weather conditions in the Gulf of Maine.

These buoys are like massive floating laboratories. They rise up to eight feet above the water, weigh over a ton, and are outfitted with a wide range of sensors that collect live data such as wind speed and direction, sea surface temperature, salinity levels, and more (graphic credit: NERACOOS).

A graphic of a smart buoy and all of its components.

Each buoy stores this information in a built-in computer and then transmits its data back to shore via cellular and satellite technology. Back on land, systems developed by the University of Maine and GMRI receive that data and translate it into information that can help those who work and play on the ocean know what conditions are like at sea.

To remain valuable, all of the bells and whistles on these buoys must continue to function in the worst weather the Gulf of Maine can throw at them — a notion not lost on the buoys' caretakers.

Imagine it's the dead of winter in the perfect storm. There’s a buoy way offshore, the waves are 30 feet, there's 100 pounds of ice on its frame, and it still has to do its job. These buoys become special. We root for them, we think about them, and when something happens to them, we get kind of upset about it.

Riley Young-Morse Senior Program Manager

These buoys provide the crucial information that feeds practical applications such as meteorological forecasts, ocean simulation models, and near real-time products like the Mariner’s Dashboard — a NERACOOS tool designed to help anyone who goes out on the ocean understand current ocean conditions.

As a Senior Developer on the ODP team, Alex Kerney helps build and manage the Mariner’s Dashboard. This application gives fishermen, sailors, surfers, and others accurate and up-to-date information about ocean conditions before they head out to sea.

In this edition of Gulf of Maine, Explained, Riley Young Morse gives us a deeper look at NERACOOS buoys and how they support people who depend on the ocean.

The data is also helpful in making weather forecasts, as wind and water temperature conditions drive much of Maine's weather. That’s why we also share this information with the National Weather Service to help inform their forecasts.

Data from NERACOOS buoys also influences various weather models — including the short-term, regional High Resolution Rapid Refresh (HRRR) model — which has many practical applications, such as allowing power companies to make decisions about when and where it’s safe for line workers to begin restoring power.

During a storm, line workers cannot work on the power lines when the wind is above 30 miles per hour. The power company can use the HRRR model, which is really leaning on the buoy data, to know that for the next hour, in a couple of towns, there’s going to be enough of a lull that they can get some lines fixed while they’re grounded elsewhere.

Alex Kerney Senior Developer

ODP tools also store much more data beneath the surface. Scientists throughout Maine and beyond can access a detailed, long-term log of weather data to inform climate research.

Combining the information we collect through eDNA and the NERACOOS buoys allows us to make larger observations about the Gulf of Maine ecosystems. Through eDNA data, we can see what species of fish are becoming more or less abundant in various regions of the Gulf of Maine. We can then compare this data with long-term ocean condition data to help us figure out how different species are adapting to our warming waters.

Photo credit: UMaine.
Photo credit: UMaine.

Understanding which species are thriving versus which are struggling to adapt will help us better manage the Gulf of Maine in the years to come.

Dr. Cameron Thompson, Pelagic Ecology Research Fellow at NERACOOS, explains how buoy data can help us put the pieces together when studying species distribution in the Gulf of Maine’s changing ecosystem.

"Having those buoy observations lets us put the pieces together and make connections with the species we see and the time at which we see them.

Cameron Thompson, Ph.D. Pelagic Ecology Research Fellow, NERACOOS

Like Dr. Sherwood, Dr. Thompson is also excited about the possibilities that using eDNA as a research tool creates. Dr. Thompson sees eDNA as an alternative to the challenges of determining species under a microscope.

Taxonomic identification through microscopy is really challenging. Few people have the skill set, and we often have to settle for higher taxa identification when we can't determine the species — so eDNA would be an incredible step forward.

Cameron Thompson, Ph.D. Pelagic Ecology Research Fellow, NERACOOS

The way that we observe ocean phenomena is evolving, and eDNA and advanced deep-water buoys are just two examples of innovative technology that support those efforts. Environmental DNA teaches us about species distribution and abundance without having to physically catch or even see fish. Smart buoys provide us with near real-time updates on ocean conditions and also help paint a clearer picture of long-term climate patterns. Together, these two tools become even more powerful when it comes to understanding the complexities of marine ecosystems.

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