Theme Sessions and Workshop

Conference workshop

We are excited about a very timely workshop on connectivity in marine fish populations. This workshop will be held during the afternoon of 7/23 and the morning of 7/24. The workshop will be a series of invited talks by researchers who are actively engaged in this important research front. For invited speakers, please denote your status as an invited speaker (‘INVITED SPEAKER - CONNECTIVITY WORKSHOP’) at the end of the abstract that you submit to the JMIH abstract submission webpage (step 6 of the JMIH abstract submission sequence is specific for LFC related submissions). Please confirm with the workshop organizers that you have accepted their invitation to present at this workshop and your abstract has been submitted to the JMIH website. Note that the abstract submission deadline is March 31.

Here are the details for this workshop (note that there will be a theme session on the same topic which will be open to authors whose work is aligned with this topic).

Conference Workshop: Temperate-tropical differences in connectivity – real and perceived

Organized by: Jeff Leis (jeff.leis@austmus.gov.au), Jenn Caselle (caselle@msi.ucsb.edu) and Bob Warner (warner@lifesci.ucsb.edu)

Background. Does larval dispersal in marine ecosystems differ in some fundamental ways between temperate and tropical systems? Or, do the differing backgrounds and training of those working in these marine ecosystems mislead us into thinking temperate and tropical marine systems differ much more than they really do? The purpose of this workshop is to bring together larval biologists, fisheries biologists, oceanographers and other researchers working in temperate and tropical environments to explore what differences are real and which may stem from our different approaches to working on connectivity.

Perspectives and goals differ amongst tropical and temperate workers, and this naturally leads to different research approaches. This can lead us to perceive greater differences amongst systems than may really exist. The organizers have identified a number of contrasts between temperate and tropical fish populations and in how research has been conducted in these two realms. The following list includes topics that will be addressed by the invited speakers for this workshop.

Larval biology. In the tropics, larval fish biologists tend to be ecologists by training and employment, working at academic institutions. In temperate regions, larval fish biologists are primarily fishery scientists who work for fishery agencies.

Scale. In the tropics, emphasis on dispersal has been on micro to meso scale, whereas in temperate waters, the scale has been meso to macro.

Species. Tropical fish biologists tend to work on small, non-commercial, reef species that are site attached as adults. These researchers argue that these species can be models for larger species. In temperate waters, the emphasis has been on commercial species that are often pelagic, migratory, and either large in size or exhibit schooling.

MPAs. The focus on the use of MPAs in tropical areas has been on retention and self-recruitment. In temperate areas, the focus has been on MPAs as a fishery tool, and therefore on export of larvae to support exploited fisheries.

Hjort’s two influences. Tropical workers tend to focus on dispersal/retention issues, the 2nd of Hjort’s two influences, whereas temperate workers are more concerned with Hjort’s first area of influence – food-related issues such as match-mismatch relationships in space and time.

Productivity and variability. Tropical systems are perceived as being food-poor but with low variability in space and time. Temperate systems are perceived as being highly productive yet highly variable in space and time.

Marine-freshwater interactivity. Estuarine dependence and anadromy have received little attention in the tropics, yet they are major research foci in temperate environments.

Intermediate habitats. The importance of intermediate habitats and nurseries has been much more emphasized in temperate studies than in tropical ones.

Type of dispersal. If we define dispersal of demographic significance to be that capable of replacing mortality, then the spatial scale of demographically significant dispersal will be smaller than that of dispersal that is of genetic significance. Is there a differential emphasis on these two types of dispersal in temperate vs tropical systems?

Theme Sessions

The LFC2009 will have three theme sessions, each of which is open to contributions by any author whose paper is aligned with the respective themes.

If you wish your paper to be considered for a theme session, denote this by including the following text at the end of the abstract that you submit to the JMIH abstract submission webpage (step 6 of the JMIH abstract submission sequence is specific for LFC related submissions).

ORAL PAPER - THEME SESSION ON HYPOXIA (open to all authors)
ORAL PAPER - THEME SESSION ON CONNECTIVITY (open to all authors)
ORAL PAPER - THEME SESSION ON ALTERNATIVE MEASURES OF CONDITION AND FEEDING SUCCESS (open to all authors)

Note that the abstract submission deadline is March 31.


Theme session 1: Hypoxia and fish early-life stages

Organized by: Lorenzo Ciannelli (lciannel@coas.oregonstate.edu) and Denise Breitburg (breitburgd@si.edu)

Background. There is increasing awareness and concern about the fact that vast coastal areas of the ocean are becoming more impoverished of oxygen, or hypoxic. Although the extent and pattern of hypoxia can be quite variable among ecosystems, the causes of coastal hypoxia can be traced to two major mechanisms: increased nutrient enrichment linked to human activities, and increased surfacing of nutrient-rich, oxygen-poor deep waters linked to large-scale climate changes. In some cases these two mechanisms co-occur with synergistic consequences. The Gulf of Mexico, the Chesapeake Bay, and the Adriatic Sea in the Mediterranean, are examples of ecosystems where recent increases in the intensity and frequency of hypoxia events originate largely from an increase in nutrients related to human activities. The shelf region of the Pacific Northwest of the United States, which is part of the California Current System of eastern boundary zones, provides an example of hypoxia caused by the surfacing of nutrient-rich and oxygen-poor deep waters. Coastal hypoxia caused by human-driven enrichment may be more persistent in space and time, while hypoxia events driven by ocean circulation are confined to the upwelling-favorable seasons and locations. The earliest life stages of fishes are more vulnerable to low oxygen than are juveniles and adults due to lower physiological tolerances and limited mobility of younger fish. Low oxygen can negatively affect marine fishes in a variety of ways, including behavioral responses, habitat changes, physiological stress, and increased predation, starvation, and mortality in the newly colonized habitat. Low oxygen can also indirectly affect fishes via a disruption of energy pathways within the community with latent population effects caused by increased mortality during the early-life stages. There is a need to better understand the mechanisms through which low oxygen exposure affects fish early-life stages and the consequences of these effects at the population and ecosystem levels. This session will be devoted to field, modeling, and experimental research focusing on the effects of hypoxia on fish early-life stages. We invite contributions that emphasize various levels of responses of fish to low dissolved oxygen including, behavioral, physiological, and interspecific interactions, and that adopt a variety of approaches, including experimental, field and modeling work. Given the highly variable nature of the onset, duration, and extent of coastal hypoxia, both proximate and ultimate effects on fish early-life stages may vary considerably from one system to another. Therefore, we also welcome synthesis and field studies comparing the effect of hypoxia among ecosystems.


Theme session 2: Temperate-tropical differences in connectivity – real and perceived

Organized by: Jeff Leis (jeff.leis@austmus.gov.au), Jenn Caselle (caselle@msi.ucsb.edu) and Bob Warner (warner@lifesci.ucsb.edu)

Background. (This theme session is in association with the workshop hosted by the same trio. It is open to contributions by any author whose paper is aligned with this theme. Please see the description of the workshop for general background.)


Theme session 3. Alternative measures of condition and feeding success

Organized by: Louise Copeman (lcopeman@mun.ca), Ben Laurel (Ben.Laurel@noaa.gov), Francis Juanes (juanes@nrc.umass.edu)

Background. Fish condition factors have generally been measured as a function of weight and length. Similarly, feeding success often is assumed to be proportional to stomach content weight. More recently however, it has become clear that condition may also depend on various aspects of tissue quality such as lipid classes and fatty acids. Lipid/fatty acid analysis, along with new techniques using bulk and compound specific isotopes, provide additional information on feeding success, prey selection and trophic connectivity. Physiological constraints and the environment are factors to be considered when applying new methods to evaluate condition and feeding history. To date, much of this work has focused on maturing adults or fish in aquaculture situations. This session would bring together papers that describe alternative measures of body condition and feeding success in larval and juvenile fishes with a focus on new techniques.