Tracking Fish Forwards and Backwards Using High-Tech Tools
A TALK BY HEIDI DEWAR
Dr. Dewar at Work
(Photo permission from Heidi Dewar)
Dr. Heidi Dewar, Fisheries Research Biologist at NOAA Southwest Fisheries Center in San Diego, is an expert on large pelagic fish, including tunas, sharks and swordfish. Her research has focused primarily on physiology, migratory patterns and habitat use.
Dr. Dewar will discuss the importance of tracking the movement of individual specimens, which informs population structure, habitat use and potential sources of mortality and is critical to management, conservation and understanding basic biology. She will discuss the high tech tools that she and other scientists use to accomplish this. These include ever more sophisticated electronic tags for forward tracking in time, and analysis of complex chemical signatures of captured individuals. These tools are used to perform backward tracking in time, determining such things as the oceanographic region the fish had been in and the time frames involved.
Together these tools help to address complex questions about fish in their natural environment, and to better manage complex international fisheries and predict potential changes in abundance and distributions with climate change.
FROM THE PRESIDENT
Memories, Memories, Memories
We are beset with thoughts about MEMORIES and the MEMORIES themselves. They are a treasure trove, Pandora’s Box, the glue that holds us together, entry to our mind, our history, identity, self. Most of us view memories as accurate depictions, replays of our experience, and that of others. We assume that our recollections are permanent, fixed. But then, we experience some blurring, fragmenting, or losing of reminiscences--observed in others or ourselves.
Personally, I was jolted into thinking about the fragility of memory by reading a journal article just last December, viz.,“The adult brain makes new neurons and effortful learning keeps them alive”. The article asserts that the brain produces thousands of new neurons, nerve cells, in the hippocampus each day throughout life. However, in testing animals, researchers discovered that a significant number of the hippocampal neurons die within a few weeks unless the laboratory animals experience a specially designed form of training, in which their learning is new, effortful, and successful.
With successful training, many of the recently generated cells in the hippocampus are rescued, differentiated into neurons, and form synapses. They generate action potentials, firing, as they are incorporated into the existing architecture and functional circuitry of the adult animal brain. Other research demonstrates functional neurogenesis in the adult (mouse) hippocampus. WOW!
Amazing discoveries, but what are the limits in terms of animal age, viability of the new cells, etcetera? And, most importantly, are these discoveries applicable to humans and our memory systems? Anyway, what do we know about human memory systems, their flexibility, viability, stability, and the effects of training on preserving human brain structures, memories, cognitive functioning? I really wish that there were information on this topic.
Well, be careful what you wish for!! Because, another journal just came in the mail with an article on “Cognitive Shields, Investigating Protections Against Dementia”. This article reports important research about the relation between signs of dementia in human post-mortem brains versus the same people’s lifetime absence of dementia symptoms which leads to a research review of ways in which various conditions may serve as mental buffers to help people maintain memory later in life.
This research report and my own literature search goes beyond the space and focus of this column, so, please stay tuned for next month’s musings on this topic. It will continue to provide a glimpse into various conditions – physical activity, cognitive training, learning experience, biochemical, genetic – which may affect humans mental functioning in later life. Will we remember to have a look at next month’s Newsletter to see if we continue this discussion? After all, memories are not just a receptacle of the past and present, but an entry to the future as well.
With best wishes,
Sue R. Rosner
Tentatively, Colloquy Café will meet on the third Wednesday of the month, March 18, at 1:30 at the Vi. Please contact Mary Ellen Stratthaus for confirmation.
Culture One will meet on Tuesday, March 17th, at the Vi, 2 – 4 PM, to discuss two study group ventures. First, we will compare notes on the CARTA February 20th Symposium, “How Language Evolves,” preparing to view the program video when released in April.
Second, we will preview the groundbreaking material of the upcoming CARTA Symposium, “Human-Climate Interactions and Evolution: Past and Future,” to be held Friday, May 15. It deals with the controversy of how planet climate change may have influenced human evolution and considers how and when humans became a force of climate change.
It also presents the intriguing idea that the planet has entered a new geological phase, the Anthropocene, or age of humans. This raises questions regarding the human transition from apelike ancestors in Africa to its current planetary force, as well as the future prospects of world climate, ecosystems, and our species. We invite you to join us in researching this material and sharing it with others in SDIS and the community.
Contact Sue R. Rosner, firstname.lastname@example.org, for information and meeting plans.
The Culture Two Study Group expects to conclude its attention to India Calling by Anand Gibidharadas at its next meeting, 1:30 PM, Friday March 27.
Following that, the group’s attention will remain on India but it will use a different text for background reading, one with a more macro focus, actually a series of essays in a book titled Reimagining India.
Contact Sam Gusman at email@example.com for further information or to learn about attending meetings of this group.
The Film Group will meet Wednesday, March 4 at 10:00 a.m. at the home of Barbara Heckler to view the 1962 drama To Kill a Mockingbird. Based on Harper Lee’s novel of the same name, it is considered one of the best films ever made. Contact Barbara at firstname.lastname@example.org for information about attending.
The Literature Group’s next meeting will be on Friday, April 10th, at Marcus Klein's. Nancy Cohen will lead us in a discussion of W. Somerset Maugham’s Moon and Sixpence. We meet at10:30 a.m. and eat lunch afterwards. We all bring our own "brown bag" lunch; the host provides dessert. We welcome new members! If you would like to come, please give Marcus Klein a call.
The next meeting of the Neuroscience Study Group is scheduled for Thursday, April 2, at 3 pm at the apartment of Bea Rose at the Vi. The reading assignment is Damasio"s Self Comes to Mind, Chapters 7 and 8 in part III—where Damasio promises to reveal all.
Visitors are welcome; however due to the constraints of space, it would be wise to call Bea Rose first to ensure a place, email@example.com.