is a database comprising 200,000 names of algae—fossil and extant, unicellular and multicellular, fresh and marine.
Although he specialized in the genus Codium, a globally distributed genus, Paul’s heart remained on our Pacific coast. His thousands of specimens resulting from numerous collecting trips throughout the California Channel Islands and along the “Lost Coast” of northern California represent some of the finest we have. His profound knowledge of the history and diversity of our beautiful West Coast seaweeds lives on in his brilliant publications and specimens.
Kathy Ann Miller
University Herbarium
University of California at Berkeley
Paul Silva, whose contributions to our under-standing of seaweeds are enormous. Photo by Kathy Ann Miller
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as it’s growing can be heavily influenced by its environment (see Seaweed Communities, p. 247). Callophyllis edentata (p. 132), for example, might be tall with wide branches in a sheltered cove or short with fewer narrower branches on a wave-swept open coast. Finally, for many species an accurate ID requires knowing the habitat or features of a particular reproductive state. For specimens found washed ashore or those lacking reproductive structures, absolute identification is not possible.
What if you could use DNA to identify organisms and reduce or remove the challenges of morphology? That was the idea of Paul Hebert and colleagues from the University of Guelph when, in 2003, they proposed that DNA could be used to identify most species of animals, plants and fungi. Hebert called it the DNA barcode. The barcode is a short stretch of DNA from a certain gene in the mitochondria of cells (mitochondria are the energy-producing “engines” of our cells and contain their own DNA). Here, instead of the cashier scanning your groceries to find the prices, you could sequence the DNA barcode of an unknown seaweed, check that code against a reference library of all known species and voilà! Identification made. If your specimen doesn’t match a species in the library, then you may have uncovered something new. As of July 2015, this Canadian-driven initiative has generated 4,593,176 sequences for 249,479 species of life. The physical specimens are housed in museums and herbaria around the world, with the DNA barcode library online—Barcode of Life Data (BOLD) Systems—and housed at the University of Guelph.
At the University of New Brunswick, G.W. Saunders and his lab (including BEC during her PhD) have been developing and populating the DNA barcode library with seaweeds since 2004. This work complements Saunders’s career studying the diversity, relationships and evolution of seaweeds around the world. The Saunders Lab has “barcoded” more than 12,000 Canadian seaweed specimens, uncovering dozens of species previously unknown in these waters, and provided invaluable new information about where species are distributed. One such new species is Saccharina druehlii (p. 205), named in honour of LD. Other scientists contributing to this exciting and important work are Patrick Martone, Katy Hind and Sandra Lindstrom (University of British Columbia); Paul Gabrielson (University of North Carolina); Jeff Hughey (Hartnell College); and Kathy Ann Miller (University of California, Berkeley). Many of the taxonomic updates included in this revision are thanks to their efforts, but much work remains before we know the full
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About Seaweeds
richness of our marine heritage. A curious phenomenon arises from the use of DNA identifications. As you will discover in the species descriptions, often what was thought to be a single species, as defined morphologically, was discovered to be composed of many molecular species. In some instances, these molecular species have not been described morphologically and, often, when their morphologies have been compared, no distinguishing features have been noted. These are cryptic species … and very frustrating to the field biologist.
The initial and ongoing application of the DNA barcode was to describe and catalogue our biodiversity. As the library grows, new and powerful applications are emerging, such as revealing mislabelled food, herbs and other products. In one scandalous example, endangered fin, sei and minke whales were discovered being served as sashimi at several restaurants in California and Korea. Other endangered animals and plants have been tracked, including products such as “bushmeat,” meat from wild animals, especially in Africa and Asia, which can carry human diseases. Border agencies have used barcoding to document invasive species and crop pests in agricultural products. Steve Fain, who pioneered kelp DNA phylogenetics while at Simon Fraser University, now works for the US Fish and Wildlife Service. He uses forensic DNA studies to catch traffickers. For example, he has discovered mislabelled caviars from endangered species.
Paul Hebert envisions a not-too-distant day when barcoding can be done with a handheld device (think Tricorder from Star Trek). Until then, and maybe beyond, beachcombers and botanists, school groups and scientists alike will still use field guides and taxonomic keys to explore their world. So look sharp! And look closely. You never know when something new has crossed your path.
Beach Etiquette, Collections, Safety
As you stand on the shore, enjoying the splendour around you, consider the myriad plants and animals gasping under your boots. Anyone who ventures into the intertidal region has an adverse impact on its inhabitants, but we can minimize this impact. If you turn a rock to see what is under it, roll it back into its original position. Collect specimens only when you must. The seaweeds described in this guide can be identified in the field without being disturbed. British Columbia and all western US states have regulations governing the collection of seaweeds; become aware of these. The Nutrition and Cooking
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section (p. 281) points out the advantages and joys of eating seaweed, but this is not an endorsement of wild foraging. Sea vegetables are commercially available, having been produced on farms or harvested from the wild under controlled, sustainable conditions.
If you must make collections, do so sparingly and never remove a rare seaweed—take a photograph. A correct scientific collection requires that the entire organism be removed, as the nature of the attachment organ along with the more conspicuous plant parts are important in making detailed identifications. If you collect into plastic bags, remember that they turn into miniature greenhouses if exposed to the sun, quickly cooking your algae. Keep specimens of the brown seaweed Desmarestia (p. 193, 198) separate from other seaweeds. Desmarestia releases sulfuric acid when in captivity, which will destroy your other collections.
The best way to preserve seaweeds attractively is to press them to dryness. Arrange fresh plants on quality paper, such as herbarium paper. Fine-structured plants may be floated on the paper from a shallow tray containing seawater and then teased into a striking arrangement with a watercolour brush and needle. Then cover the plants with a clean cotton cloth and press them in a plant press. A
