What’s in a Wrack Line?

By: Brian Chan and JulieAnn Prentice, Birds Canada
The wrack line is an essential microhabitat on beaches, sustaining a wide diversity of invertebrates and shorebirds, including the endangered Great Lakes Piping Plover. Despite this importance, most people are unaware of what wrack is or where to find it. So, what exactly is a wrack line? Wrack lines consist of organic materials like driftwood, plant matter, and algae that wash up with the waves, forming a long strip of debris along the water's edge. As wrack breaks down, it creates an ideal habitat for invertebrates to feed and reproduce, attracting larger predatory insects and forming a hidden ecosystem.

Wrack along the shoreline of Georgian Bay, Ontario. Photo Credit: Birds Canada

However, insects are not at the top of the food chain in this habitat. Every year, thousands of shorebirds flock to the coastline of the Great Lakes during migration, taking advantage of insects in wrack to fuel up for their long flights. The Great Lakes and their tasty wrack are merely a pit stop for most of these birds, but for a few special species, they provide an important breeding location. Piping Plovers are one of these species!

Piping Plovers are small, sandy-colored shorebirds that are endangered both federally and provincially. After being extirpated from Ontario for 30 years, they returned in 2007. Their ideal breeding habitat is the wide, sandy beaches of the Great Lakes. Since Piping Plovers exclusively eat invertebrates, wrack is essential for their survival. Unfortunately, wrack is often considered unsightly and dirty, leading to its removal through beach grooming, which eliminates this crucial habitat feature.

Pebble, a Great Lakes Piping Plover hatched in 2023, taking a momentary break from foraging in the wrack along the Lake Ontario shoreline. Photo credit: Marsha Duggan

Knowing this, you may be wondering how you can help!

Following “Leave No Trace” principles is a great start. Feeding wildlife and leaving litter on beaches attracts predators of Piping Plovers. When you enjoy a day at the beach, don’t share your food with the wildlife and take your garbage home with you for proper disposal! As well, be sure to leave the beach features as you found them. Leave pebbles, rocks, driftwood and other beach debris where it is so that wildlife can use it. Wildlife, like Piping Plovers, often use these features to hide and protect their families from threats.

Encouraging local governments to keep beaches natural and restore wildlife habitat is an important step for long-term change. By showing cities and organizations that we prefer healthy, natural beaches over bare sand, they may be more inclined to reduce or end beach grooming efforts. These changes may attract more Piping Plover to nest across the Province!

If you’re visiting a beach with Piping Plovers present, it is important to give them space and respect. This includes staying out of fenced areas, keeping pets off sand beaches,, and ensuring you play games and sports away from protected areas. Any disturbance, even brief, can distract Piping Plovers from foraging, incubating, or protecting their chicks. Chicks need regular access and undisturbed access to wrack so that they can grow big, strong, and eventually tackle their long migrations south!

And, if you’re looking for a larger way to get involved in Piping Plover conservation, you can support by volunteering as a nest monitor, sharing information on social media, and educating friends and Family while you’re out on the beach.

For more information on the Ontario Piping Plover Conservation Program, you can follow us @OntarioPlovers on Facebook, Instagram, and Twitter (X). To report a sighting of a Piping Plover, email [email protected].