GLIN==> Two Seminars this Week (Ann Arbor)

[David Reid <David.Reid@noaa.gov>]

My apologies for this last minute notice.  GLERL is hosting two NOAA - U 
of M Great Lakes Seminars Series seminars this week:

10:00 a.m., Tuesday, November 27
GLERL Conference Room 105

Title: "The relative influence of landscape configuration and inundation 
on brown shrimp production in northern Gulf of Mexico salt marshes"

Speaker: Dr. Brian Roth,
Department of Oceanography and Coastal Sciences
Louisiana State University

Abstract:
I used a spatially explicit individual-based model to investigate the 
relative influences of inundation and habitat fragmentation on brown 
shrimp (Farfantepenaeus aztecus) production in northern Gulf of Mexico 
(NGOM) salt marshes. The model simulates a population of brown shrimp 
from their arrival in Spartina salt marsh as post-larvae to their 
emigration as sub-adults. I quantified production in terms of sub-adult 
export and trophic transfer (total shrimp mortality). I utilized a 
factorial design to simulate shrimp on all combinations of four maps 
that represented an idealized progression of habitat fragmentation and 
four inundation regimes from each of two locations in the NGOM 
(Louisiana and Texas). I also quantified the configuration of the marsh 
landscape to determine if specific metrics could be utilized as a proxy 
for shrimp production. The results indicate that inundation is more 
important than landscape configuration for determining shrimp 
production, but that landscape configuration has a strong influence on 
shrimp production within a single inundation regime. Inundation affected 
all three measures of shrimp production, primarily due to decreased 
mortality incurred when shrimp have access to vegetation through marsh 
flooding. Although the model performs well in comparison to empirical 
estimates of shrimp abundance and spatial distribution, future 
investigations will need to consider the dynamic relationship between 
inundation and landscape configuration to accurately predict shrimp 
production over longer time scales.

--------------------------------------------------------------------------------

10:00 am, Thursday, November 29
GLERL Conference Room 105


Title: "Untangling the relationships between variability in the marine 
environment, population dynamics, and community structure"

Speaker: Dr. Brian Wells, Long Marine Laboratory,
University of California, Santa Cruz;
NOAA Fisheries, Fisheries Ecology Division, Santa Cruz

Abstract:
Researchers accept that variability in the marine environment affects 
the productivity of populations, communities, and ecosystem stability. 
The challenge to conservation biologists is not only in recognizing the 
complicated mechanisms and interactions between environmental variables 
and the biological responses, but also in quantifying these factors in 
such a way as to incorporate the results into a management framework. 
Here, I broadly demonstrate, through novel statistical and field 
approaches, how the environment drives aspects of production for krill, 
fish, and seabirds along the northern and central California coasts. I 
focus on a list of ecological factors that relate to productivity: 
mortality, fecundity, age at maturation, distribution, juvenile 
dispersal, and ecosystem state. I show that variability in maturation 
age and growth rates of Chinook salmon relate to environmental 
variability in a predictable way. Specifically, an environment conducive 
to greater primary productivity during the spring promotes growth and, 
therefore, maturation during the next year. However, the mechanisms 
differ between regions along the northeast Pacific coast such that the 
distribution of the fish must be known to fit models appropriately. 
These findings can be used to adjust maturation rate schedules and 
better estimate ocean abundance of a cohort. I also show a novel 
approach to describing dispersal of juvenile rockfishes along the 
central California coast that will assist in determining 
habitat-specific mortality and condition. In doing this, I use 
remotely-sensed sea surface temperature data to define distinct 
open-ocean habitats (e.g., upwelling regions, plumes). Then, I combine 
these spatially-referenced data with shipboard collections of water and 
fish to develop distinct chemical signatures on otoliths that can be 
used to retrospectively determine habitat associations of juvenile 
pelagic rockfishes before they settle into the Monterey Bay region. 
Finally, I demonstrate that the production of a key indicator trophic 
chain (i.e., krill, rockfish, seabirds) within the larger food web can 
be related, in a predictable fashion, to the environment over a 
thirty-year period. The results of this work can be applied directly to 
improve management of rockfishes by improving estimates of year-class 
strength, and, most importantly, these results provide an indicator of 
ecosystem state and productivity.

For directions, see
http://www.glerl.noaa.gov/facil/triptik.html

--
David F. Reid, Ph.D.
Director, NOAA National Center for Research on 
Aquatic Invasive Species (NCRAIS)
Senior Research Scientist, Nonindigenous Species Program
U.S. Department of Commerce
National Oceanic and Atmospheric Administration
Great Lakes Environmental Research Laboratory
2205 Commonwealth Blvd.
Ann Arbor, MI  48105-2945
Voice: 734-741-2019
FAX: 734-741-2055
GLERL home page:
   http://www.glerl.noaa.gov

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