Eelgrass Meadows: Home to more than you think

Date: 
August 18, 2015
Author: 
Kaylyn Kwasnecha

Many people living near the water's edge in Tofino are familiar with the eelgrass meadows along the shoreline, in the harbour, and on the mudflats. To some, eelgrass meadows are just a bunch of smelly muck, sinking sand, or weeds that tangle their way into boat props. However, to others, including many marine species, eelgrass meadows are critical to life on the coast. Eelgrass meadows are extremely important to coastal ecosystems in three main ways: they provide habitat for many marine organisms and birds, their presence shapes the physical habitat, and they are an extensive carbon sink, making the meadows one of the most productive ecosystems on Earth.

Common eelgrass (Zostera marina) is present typically along sheltered intertidal areas and shallow subtidal muddy and sandy substrate in Clayoquot Sound. The meadows of ribbon-like green blades are home to more life than you probably think these cold waters of the Pacific Northwest can support. Along the edge and below the surface of the water lies a flourishing, colourful ecosystem much like the fragile coral reefs in the tropics. The substrate and canopy of eelgrass meadows provide refuge and a nursery habitat for a multitude of coastal species to begin their salty life.

Over 50 species of fishes have been observed in the meadows of Clayoquot Sound, including surfperches, pipefish, rockfishes, greenlings, gunnels, flounders, clingfish, gobies, pricklebacks, sticklebacks, tube-snouts, and sculpins. Among these fish is the colourful, big-eyed red Irish lord (Hemilepidotus hemilepidotus), which can change colours to blend in with its surroundings. The bay pipefish (Syngnathus leptorhynchus), a charismatic species related to sea-horses, likely resides in the same meadow year-round and is considered a symbol of high ecological integrity. And contrary to the  popular belief that the underwater world is silent, the plainfin midshipman (Porichthys notatus), a species of toadfish, may have something different to say: the plainfin midshipman is referred to as the singing fish, due to its loud grunting noises made by males for communicating territorial and breeding information.

Along with these fish, many crustaceans including various crabs, shrimp, isopods and amphipods are seen crawling around the muddy seafloor of the eelgrass. Molluscs including snails, limpets, bivalves, and the small, yet vibrantly coloured nudibranchs are also a part of the beauty of this unique ecosystem. Nudibranchs, such as the opalescent nudibranch, are regarded as one of nature’s wonders because their spectacular colouring and markings bring a tropical feel to the cold waters in the Pacific Northwest. Other organisms that take shelter in the eelgrass include worms, jellyfish, tunicates, sea stars, and much more. Many of these fish and invertebrates are prey for birds such as bald eagles, ospreys, sea gulls, and mammals including mink, raccoons, and humans.

Eelgrass meadows provide critical habitat for a diversity of marine life from gunnels to gulls, and are an extremely important component in the coastal ecosystem. Because of the ecological importance of these meadows, a partnership has been developed between the Raincoast Education Society, Strawberry Island Marine Research Society, the Nature Trust of British Columbia, Parks Canada, and the Clayoquot Biosphere Trust to map and monitor the health of eelgrass habitat in Clayoquot Sound.

So, next time you are out on the water fishing, kayaking, stand up paddle boarding, snorkelling or whatever you please, take a longer look into the green swirls near calm shores and you will see that there is much more than immediately meets the eye.