Healthy seagrass starts with snails, slugs and other algae eaters

Snails, slugs and a variety of other bugs are often considered pests in a garden, as they might be eating flowers and citrus trees. But for marine gardens like a meadow of seagrass, snails, worms, and crustaceans are essential for healthy growth, because in the ocean they’re not eating the grass, they’re eating the algae.

Eating algae off the seagrass is beneficial because it essentially cleans and clears space for further growth. Seagrasses grow slower than algae, and so algae can quickly overwhelm and choke out the plants that are otherwise home and habitat to a huge number of fish, sea turtles, manatees, and of course, the snails, slugs and other critters that help keep the algae at bay. The seagrass also helps absorb carbon and its roots help hold shorelines in place, so there’s a multitude of reasons to support the team of seagrass-cleaning species.

The main threats to this ecosystem are pollution and fishing. The pollution in question is primarily fertilizer runoff from human farms. The algae loves the fertilizer, and grows at an even faster rate than usual when it’s introduced. On the other side of the system, fishing ends up removing and killing off the grazing species that are trying to control the algae. No one species can do it alone, as research led by the Virginia Institute of Marine Science has found that a more diverse maintenance crew makes for measurably cleaner and healthier seagrass.

My kindergartner asked: Why is it named ‘seagrass?’ Seagrass is actually the name of a group of flowering plants. While there’s some variety to their shape and size, when growing in a ‘meadow,’ they resemble tall grass enough to warrant the name.

My two-year-old asked: What’s fishing? It’s a term originally from Middle English for catching fish. (No, I didn’t worry him with the Middle English part.)

Source: Bugs and slugs ideal houseguests for seagrass health by Kat Kerlin, Egghead