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Marine Debris Diver: We Hauled 14 Metric Tons of Derelict Nets off Maro Reef


Two Marine Debris Program staffers are participating in NOAA’s annual mission to remove derelict nets and other marine debris from sensitive coral reefs and shorelines in Papahānaumokuākea Marine National Monument, one of the largest marine conservation areas in the world. An estimated 52 tons of derelict fishing gear washes up in the Monument each year, threatening the pristine ecosystem. Follow their journey

By: Naomi Blinick

Naomi is a guest blogger and marine debris diver on the mission.  

A marine debris diver secures lines to a tangled mass of nets at Maro Reef.

A marine debris diver secures lines to a tangled mass of nets at Maro Reef.

As a new member of the marine debris team, I am both humbled and awed by what I saw in our first week of field operations at Maro Reef.  While our first day presented us with ideal conditions, we were confronted with strong currents, rain squalls, and poor visibility throughout the week. Yet in just six days, we still managed to exceed our expectations for this site and surveyed nearly 1 million square meters of area and recovered an estimated 14 metric tons of marine debris!

As you’ve read on this blog, our  recovery efforts focus on derelict fishing gear, or DFG.  This type of debris poses direct threats to marine life, by entangling animals like critically endangered Hawaiian monk seals and green sea turtles, and by snagging on delicate corals as the nets travel across a reef area.  The nets may either settle where they first catch, breaking, shading, and abrading the corals, or they may actually break the corals off the substrate and continue to travel, picking up more and more coral heads as they make their way across a reef.  They effectively turn into net purses rolling across the reef, catching up corals and rubble and becoming remarkably heavy in the process. This causes increasing damage as they smash into the substrate in current and surf.  These nets in particular are very difficult to pull up.

The actual process of pulling in the DFG has been eye-opening for me.  In training, we had a lot practice spotting debris items and calling out data to our small boats, but we didn’t have an opportunity to pull in anything big until the real work began.

Sometimes, it’s easy; we can just untangle the debris from the substrate and swim it (often with the help of our buddy) to the boat. Other times, the net, or conglomeration of multiple nets, can weigh 500 lbs or more. For these, we need to figure out how to best utilize our resources to get the DFG aboard.  Often this means tying lines to the net underwater and then hauling the lines from the boat until the main mass of the net is right off the sponson (the inflated side of the small boat).  Then, we’ll retie our lines to lower points on the mass and slowly pull it up incrementally, adjusting our lines to lower and lower points until the mass can be pulled up over the edge of the sponson and into the boat.

In some cases, the nets need to be cut into sections underwater to be able to lift them in. We had a situation like that a few days ago, and we must have cut through at least six different net-types that had all combined into one massive conglomerate. We all carry sharp dive knives for this purpose, and I’ve been amazed at how quickly mine has dulled from cutting through nets, which are often covered in thick coralline algae.

The photos may make it look like a tropical paradise, with crystal clear waters and blue skies, but it is difficult to capture the many occasions when the water is opaque with stirred-up sediment, and the topside visibility is equally non-existent due to rain. When high winds make it nearly impossible for your small boat to maintain its position and your net is too heavy to swim it out of the hole in the reef where you found it.  When you are repeatedly free diving to 25 feet and feel like you are barely making headway on a huge net, or when you have two whole boats teams (eight people) straining to pull in a mass of tangled nets aboard the boat.

It would be easy to be discouraged by what we find out here if it weren’t for our incredibly strong and motivated team.  Instead of heartbreak at the amount of debris we find, I feel pride in the amount we have been able to recover. I have a lot of confidence in this remarkably dedicated group, who every day is swimming for hours on end in search of DFG, working tirelessly in and out of the water to remove it, and ultimately transporting this debris off the reef.  Each net removed is a victory for monk seals, sea turtles, and the vast coral reefs of the Monument.  I’ve been asked several times this week if this experience is what I expected when I accepted the job.  My answer is always a resounding yes.

 If you missed it: Do you know what it takes to be a marine debris diver?

Author: NOAA Marine Debris Program

The NOAA Marine Debris Program envisions the global ocean and its coasts, users, and inhabitants free from the impacts of marine debris. Our mission is to investigate and solve the problems that stem from marine debris, in order to protect and conserve our nation's marine environment, natural resources, industries, economy, and people.

5 thoughts on “Marine Debris Diver: We Hauled 14 Metric Tons of Derelict Nets off Maro Reef

  1. I can’t imagine the challenge of getting these net masses out of the ocean . . . it’s a challenge just untangling rope and fish line from kelp on the beach! Thanks for this critical work that you’re doing . . . bless you all for what you do . . .

  2. I first saw this as a FB post. Astounding accumulation of horrendous detritus. I have a NOAA MDP page in the Conservation menu on my blog and will add the photo and a few details (if that’s ok with you). RH

  3. Pingback: Follow Along as NOAA Clears the Waters of the Northwestern Hawaiian Islands | NOAA's Response and Restoration Blog

  4. Pingback: Three Things You Should Know About Pearl and Hermes Atoll | NOAA's Marine Debris Blog

  5. Well done. We do not even have remotely the same problem in South Africa but a small clump of netting during this year’s International Coastal Clean-up of 240kg (dry) was a gigantic effort getting of a beach. Diving to get the nets out and then removing it with a very expensive vessel is what we can only dream of here in South Africa.

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