Introducing the Marine Debris Identification Guide

By Ivy Munnerlyn


If you’ve ever done a beach cleanup in Humboldt County, you’ve probably run across something that makes you ask “what on Earth is this”? It’s easy to identify a plastic food wrapper or bottle cap, but when it comes to the wad of brightly colored rope or scrap of black plastic mesh, it can get a lot trickier. More often than not, these hard-to-identify  items originate in the fishing, mariculture, and hunting industries. For those of us not involved in those industries, it can be next to impossible to know what we are looking at. Former Coastal Programs Coordinator Casey Cruikshank saw the need for a clear, easy-to-use guide that could help volunteers ID these items. With the help of the Coastal Programs Advisory Committee, the NEC has produced just such a guide. Here’s a sneak peak at some of the items it covers.

Crab Fisheries Debris

For both recreational and commercial crab fishermen, losing gear to strong ocean currents is a frustrating and costly part of the job. Fortunately, many people tag their gear with identification numbers or phone numbers to call in case the gear is found. If you see crabbing gear with any of these markings, please send us a location and photo! We can try to locate the owner and get the items returned. Below is a list of a few types of debris  from the crabbing industry that frequently wash up on Humboldt beaches.

Crab Pot

Crab Pot:

These are large, heavy circular traps with netting. Pots can be difficult to remove from the beach, so you may want to call in backup! If you find large items like this that you are unable to move, you can always give us a call or email us the location of the item and we can find a way to remove it. Crab pots are expensive to replace, so look for a phone number or tag identifying the owner. Chances are, the owner will be happy to hear their gear has been found and may even come help you pick it up. 

Crab Buoy

Crab Buoy:

These buoys are made of  lightweight cylindrical foam, and can be found free floating or attached to rope. They are usually yellow, orange, or white with a red stripe and are used by many as a fun yard decoration.


Oyster Farming Debris

It’s well known that Humboldt county is the oyster-farming (or “mariculture”) capital of California. Just like the crabbing industry, mariculture operations can lose gear and debris to strong currents. Luckily, many of the companies in the Bay will accept returned gear. If you find an oyster basket marked “CSC”, you can return it to Coast Seafoods Company in exchange for free oysters! If you find marked or labeled mariculture gear, please send us a photo and location so we can let companies know where their items are washing up. 

Oyster Basket

Oyster Baskets, Bags, and Trays:

Oysters can be grown in different containers depending on their stage of growth and the type of growing operation. Oyster baskets are black mesh cages measuring roughly two feet long, and can sometimes have a buoy attached. Oyster bags are made of the same black plastic mesh as baskets, but are more flexible and open on one side. Oyster trays measure roughly 2 ft x 2 ft, and are made of stiffer black mesh divided into four sections. 

Black ABS pipe

Black ABS Pipe:

In the last few years, volunteers have noticed a peculiar marine debris item on Humboldt beaches: black plastic pipe cut into 6-8 inch sections. We believe this pipe is related to past mariculture operations in the Bay, and are actively monitoring the issue.

3 Strand yellow polypropylene rope

Yellow 3-Stranded Rope:

Like the black ABS pipe, this debris item has become a significant issue in recent years. It is made of three yellow plastic strands wound together, and is typically found in cut segments of 1-2 feet. This is a common type of debris to see on Clam Beach, and is often found stuck in dune grasses. 


 If you’ve collected trash data using the NOAA Marine Debris Tracker App, you may be familiar with some of these items, which appear in the “Fishing/Mariculture/Hunting” category. The Marine Debris Identification Guide was designed to be a companion to our citizen science data collection efforts. Collecting data on the litter we find helps us advocate for trash reduction solutions in our community. If you find something that isn’t in the guide, send a photo to and we can add it to future editions. The Marine Debris ID Guide can be accessed on your phone or computer through the NEC website, or you can check out a printed copy at our office.