Although Walter Adey's specialty is coralline algae (calcified, lichen-like red algae that grow from the tropics to Arctic marine waters), he has carried out extensive field work from Arctic to tropical North Atlantic and Caribbean on a wide range of seaweeds. He has concentrated his research on ecological studies using quantitative analyses of biomass and area cover.

Fig. A
Fig. A   (click to enlarge)
Diagramatic representation of a portion of the Thermogeographic Model developed by Dr. Adey and Dr. Robert Steneck of the University of Maine and published in the Journal of Phycology in 2001. The Model shows how concentrations of coastal area at different temperatures over the last 3 million years have produced regions that are known to also produce a rich biota (biogeographic regions). The blue contours show the abundance of subarctic coralline algal species relative to the Model.
  Fig. B
Fig. B   (click to enlarge)
Northwest Atlantic Subarctic rocky shore community with the sedimentary restriction of rocky bottoms (in protected waters), Turnerella pennyi dominance below 25–30 m, the abundance of Desmarestia viridis, patchy Agarum and Ptilota beds, and scattered Saccorhiza dermatodea in the extensive Alaria kelp beds. The rocky pinnacle, or Saccharina refugium, has been added as a representative of a wide range of isolated hard bottoms in protected bays.
Fig. C
Fig. C
Preparing to dive in Labrador to harvest seaweeds from meter square quadrats of rocky bottom. The biomass data from hundreds of quadrats from Labrador to Cape Cod are being used to further test the Thermogeographic Model, the validity of which was previously demonstrated by percent cover of coralline algae on rocky bottoms.
  Fig. D
Fig. D
Divers working on an Agarum savanna in Newfoundland. For biogeographic surveys, all seaweeds are collected from m 2 quadrats and bagged for analysis aboard the research vessel. A range of depths from the intertidal to 30 m are typically surveyed. .
Fig. E
Fig. E   (click to enlarge)
Bray-Curtis multivariate similarity ordination plot. This graphic shows the strong difference between the seaweed composition of NLQ (Subarctic) stations and the Gulf of Maine (GOM) and Southern Nova Scotia (SNS) stations in the transitional (Subarctic/Boreal) zone. The deepest depth zones at exposed stations in GOM and SNS crossover into the range of the Subarctic; this results from a strong thermocline, and colder temperatures at depth.

Copyright © 2008-2013, Walter H. Adey, PhD.