Red Seaweeds
Traditional seaweed harvesters in Klukwan and Haines have observed changes in the abundance of red seaweed. Community members are interested in learning more about potential drivers of change, including flavor, if there are differences between harvest sites, and how harvest could be affected as the glacial landscape shifts.
As glaciers melt, the pressure they exert on the continental crust surrounding the Gulf of Alaska lessens. Because of this phenomenon, called isostatic rebound, scientists hypothesize that the rocky intertidal sits higher above the sea surface than in the past. Coastal residents have noticed this change. The rocky shore band in upper Lynn Canal is limited, and because red seaweeds depend on it as a habitat to anchor, a change in the tidal line would mean a change in the time to which seaweeds are exposed to air and terrestrial conditions during low tides.
The Interface of Change red seaweeds research team, therefore, hypothesizes that this increased exposure would affect metabolic responses of this important food source.
Hypotheses:
| 1.) Changing freshwater discharge patterns will increase turbidity, lower temperature, reduce salinity, and modify sources of nutrients from surface and groundwater inputs to the coast, which will decrease biomass and nutritional quality of Devaleraea mollis and Palmaria hecatensis. |
| 2.) Target red seaweeds will show reduced photosynthetic activity and growth rates, and increased stress responses when exposed to turbid and colder water typical of glacial estuaries. |
| 3.) Increased exposure to air and freshwater driven by longer periods of emersion will facilitate increased consumption rates by local herbivores, contributing to a significant reduction of harvestable red seaweeds (Devaleraea mollis and Palmaria hecatensis). |
To study changes in red seaweed growth, a team of 花椒直播researchers and community members collect samples of these red seaweed species as well as sea water sample twice per month during their growing season from March to June.
花椒直播graduate student Lindsay Meyer and Chilkoot Indian Association environmental scientist Meredith Pochardt collect red seaweeds samples.
The team includes professor Schery Umanzor, graduate student Lindsay Meyer, Alaska EPSCoR advisor and Klukwan schoolteacher Justina Starzynski-Hotch, and Chilkoot Indian Association environmental team members Liam Cassidy and Meredith Pochardt. The seaweed samples are then processed, and their chemistry is compared with that of the sea water to determine the environmental effects on seaweed growth, nutritional quality, and photosynthesis.
Photo courtesy of Lindsay Meyer.
Mariculture lab technician Maribel Montiel, Klukwan residents Justina Starzynski-Hotch
and Don Hotch, and Liam Cassidy of the Chilkat Indian Association assist with spring
sampling.
A sample vial of a young frond of red seaweed.
At the , professor Patrick Tomco and postdoctoral research Monica Brandhuber lead fellow researchers on processing the seaweed tissue and seawater samples and performing lab analyses to correlate seaweed metabolites with nutrient levels in the seawater.