The Seascapes

The Seascapes

Tuesday, June 22, 2010

What is a seascape & why make this site?


This is a collaborative tool for a research project we designed to better understand the ways ocean processes structure fish communities and affect the dynamics of fish populations. The two volumes in the image above show the bottom classified by sediment type and depth, as well as the overlying water column in two areas east of Sandy Hook, New Jersey and south of Long Island, New York.   These are our two seascapes. The arrows show very simplified flows of surface (cyan) and bottom water (darker blue) through the two volumes.  These different flows bring nutrients, plant production, detritus and the larvae of organisms through the seascapes, and could cause them to have different species and food webs.

We define a seascape as the features of the bottom and water column that affect the growth, survival and dispersal of organisms that use them.  Because most marine animals are nearly neutrally buoyant and cold blooded, "habitats" in the sea have both horizontal and vertical spatial dimensions and are very dynamic in time.  The characteristics of the water column are often more important than bottom characteristics for marine animals.  Since important characteristics of ocean "habitats" that affect the growth, dispersal and mortality of organisms can be delivered by currents from sources upstream, we consider upstream sources and transport processes to be essential components of "habitat" no matter how remote the source habitats are in geographical space or in time.  Because distant habitats in the ocean can be so strongly connected by currents and movements of organisms sometimes we prefer the word "seascape" to "habitat" which can imply a degree of isolation and independence more appropriate to land environments.

Next week we will spend 4 days sampling the planktonic larvae of fish and invertebrates in the vacinity of the two seascapes. The routes larvae take from the spawning grounds of their parents to their juvenile nurseries, and the prey and predators they encounter along the way, are controlled by the dynamic features and processes of the water column.  As a result we intend to sample larvae in relation to those ocean features and processes rather to features fixed in geographic space like bottom depth.  Sampling in "oceanographic feature space" rather than "geographic space" is possible because our seascapes lie within the footprint of a fully operational integrated ocean observation system (IOOS)  (http://rucool.marine.rutgers.edu/ & http://www.marcoos.us/).  Over the next next few days I intend to compile information about the state of the ocean so we can better understand what it has been up too.  With a better understanding of recent ocean history, we should be better equipped to identify the features and processes in the seascapes fish might "care" about and design a better adaptive sampling strategy on the fly.

Below is a nice image Jeff Pessutti made that overlays satellite sea surface temperatures and surface currents measured with HF radar on the two seascapes.  The SST and current data were provided by Josh Kohut of RU COOL http://rucool.marine.rutgers.edu/index.php/COOL-Data/ and MARCOOS http://www.marcoos.us/.




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