July 2016

Sex on the beach: is there a better way to spend a beautiful August afternoon?

First Published on July 20, 2016 Written by The Bowen Island Conservancy

The Bowen Island Conservancy is looking for some volunteers to help us with a Forage Fish Sampling Blitz, from 1:00 pm to 4:00 pm, on the afternoon of Saturday, August 6th.

What are Forage Fish? They are the cornerstone of marine food webs and are essential food for seabirds, marine mammals, and fish. Multiple species spawn on sandy and pebble beaches around Howe Sound and elsewhere in the Salish Sea. We are mostly aware of herring, which have been seen in increasing numbers in Howe Sound in the last few years. As well, juvenile salmon forage along the high tide line, feeding on land-based insects swept to the ocean’s surface by winds, and on tiny invertebrates living within the beach seaweed wrack line.

What species are we looking for here? We are interested in Pacific Sand Lance, Capelin, and Surf Smelt. These fish form massive schools which are often measured in metric tons, since they are so large. You can learn more about these fish with a quick Internet search, but to give you some high-level information about just one species, let’s look at the Surf Smelt. At maturity these fish will be about 20 cm long, and a typical fish shape with olive green backs and silvery bellies. They have relatively short lives of up to about 5 years, and spawn on beaches in summer and winter. The embryos are usually found buried just below the surface of beaches, between 2 and 4 metres below the high tide line. Watch where you tread next time you’re on a beach!

In 1904, at the peak of commercial harvest, 230 metric tons of Surf Smelt were caught in BC. In 2002 the catch was just 710 kg. As we all know, a number of fish, seabird, and marine mammal populations are in steep decline in BC, and scientists have now started to look at the link between forage fish biomass reduction and these declining populations. For example, 35% of juvenile salmon diet is made up of Pacific Sand Lance, so these fish are critical elements of the food chain that leads to our tables.

Why is there a “Sampling Blitz” taking place? In 2014, Conservancy members formed an Island team that conducts periodic surveys of certain Bowen Island beaches to test for the presence of forage fish eggs This is part of a much larger effort, coordinated by the Sea Watch Society and involving many other communities, to determine the locations of spawning beaches, and estimate the growth in population of these important species.

To date we have not found any evidence of forage fish eggs on Bowen Island. We know that other Howe Sound communities have found eggs, and that they are also present on Sunshine Coast and West Vancouver beaches, but nothing has shown up here. And we don’t know why. Possibly there’s something about our beaches that makes them unsuitable for spawning (could be the length of the beach, or the mix of sand and pebbles, or something else). But we want to sample as many beaches as possible in one day in August, which is peak Surf Smelt spawning season, to see whether we are able to obtain a positive result.

How will the blitz work? We are going to work from 1:00 pm to 4:00 pm on August 6th. We’ll divide into two teams, and sample as many beaches as we can. We’ll try to include Pebbly (Cape Roger Curtis), Tunstall South, Tunstall North, Sealeigh Park, Bowen Bay, Bluewater, Galbraith Bay, Smuggler, Cates Bay, Eaglecliff, Pebbly (Deep Bay), Sandy, Snug Cove, Seymour Landing, September Morn, and Alder Cove beaches.

Do I need any qualifications to participate? No, we welcome everybody’s help. We are particularly interested in having children participate: they always enjoy themselves and make the sampling event special.

Do I need to bring anything to sample? All you need to do is dress to match the weather. A hat and sunscreen is probably all you’ll need (we hope that nobody needs rain gear!). And we’ll supply everything else that’s needed for sampling, so you just need to show up.

How do I learn more? Send us a quick email message at “info@bowenislandconservancy.org”, or call 604.612.6572, and we’ll get back to you with more details.

What happens afterwards? After sampling we will meet from 4:00 pm to 6:00 pm, with refreshments and snacks, to celebrate a job well done. We’ll process the afternoon’s samples by sieving to concentrate the fine material, and hope we find some fish eggs! And later we’ll be sending our samples to Vancouver Island to be analyzed. We’ll be sure to let everybody know the results once we have them.

We hope that you will be able to join us as we search for evidence of Sex on the Beach on Saturday, August 6th.

 

© Copyright 2016