The Witman Lab @ Brown
Contact us!
  • Home
  • Current Projects
    • Predator diversity and the strength of trophic cascades (GMR)
    • Effects of biodiversity on temporal stability and resilience of subtidal marine communities: a global evaluation
    • Responses to El Niño events in Galapagos subtidal ecosystems
    • Decadal scale losses of foundation species and ecological consequences (GOM)
    • Conservation protection for Cashes Ledge (GOM)
  • Published Research
  • Teaching
  • Outreach
  • Lab Members
    • Jon Witman
    • Robert Lamb
    • Franz Smith
    • Becca Ward-Diorio
    • Glennie LeBaron
    • Noah Medina
    • Leif Dykstra Deschenne
    • Lucinda Anderson
  • Blog
  • Gallery

Recent presentations by Jon Witman and undergraduate researcher Fiona Beltram

11/17/2017

2 Comments

 
Picture
Participants of the workshop on climate change in the Galapagos pose for a picture, including Jon Witman (second from left, back row), Pelayo Salinas de Leon, Boris Worm, Daniel Pauly, and other members of the Charles Darwin Station, Galapagos National Park, visiting scientists, and the Ecuadorian navy.
Picture
Jon presents his keynote talk on the response of Galapagos marine ecosystems to climate change
In a keynote talk at the International Climate Change Workshop for the Galapagos Islands on October 25th, Jon Witman outlined the ecological impacts of three El Ninos on the underwater realm of the Galapagos Marine Reserve that he and colleagues Franz Smith and Robert Lamb have measured over the last 18 years. He likened the long-term impact of the El Nino climate oscillations to a roller coaster. That is, the El Nino warm phase represents a period of stress for marine life with high temperatures and scarce planktonic food, potentially decreasing population numbers and the diversity of bottom dwelling marine life – the downhill phase of the roller coaster. 
Picture
Barnacles and other filter feeding invertebrates festoon the pinnacle at La Botella, one of our long-term monitoring sites
Picture
Witman lab technician Eliza Moore poses next to a bleached Porites coral
One sign of stress was that massive and finger corals turned white (bleached) during a broad temperature regime ranging from 30 to 16 o C in 12 months as the cool nutrient rich La Nina period followed the warm phase. For example, chlorophyll a, a measure of planktonic food concentration increased 7-fold during La Nina. Thus the team speculated that the ecosystem bounces back a certain degree during La Ninas – rolling uphill on the coaster, demonstrating resilience. A surprisingly consistent response seen during all 3 La Nina events was that barnacles settled and grew all over the rocky bottom and on the stressed corals down to 20 m depth. This represents a boost to the food chain as many species of fish and snails feed on the barnacles. It appears that the La Nina- increased barnacles may be slowly displacing corals. While corals did not bleach as much as previous El Ninos during the strong 2015-2016 El Nino, we observed a diverse range of ecological impacts from skin disease in reef fish to intense sea urchin grazing and a bloom of cyanobacteria at some oceanic sites. Our work underscores the importance of sustained ecological monitoring to detect the impact of climate oscillations in the ocean.
Picture
Fiona poses with her poster at the Ivy League undergraduate research symposium
Fiona Beltram traveled to the University of Pennsylvania for the inaugural Ivy League Undergraduate Research Symposium (ILURS). The symposium consisted of 200 undergraduate students from Ivy League schools who were involved in independent research at their respective schools. Most students presented posters, while others gave short talks. Guest lectures by University of Pennsylvania and visiting faculty were also arranged throughout the three-day conference. Research topics ranged from art history and public health to astronomy and cancer research. Fiona gave a poster presentation detailing the results of her current work, which will serve as the first two chapters of her thesis for honors in the Biology degree. She is studying the appearance of cyanobacterial mats on the Galapagos reefs, the potential for a temperature-mediated introduction mechanism that is closely tied to El Niño extremes, and the ecological effects of the species’ continued presence on the reef. 
2 Comments
    Follow the Witman Lab's adventures, on land and at sea @witmanlab on Instagram and Twitter!
    Picture

    Archives

    January 2023
    November 2022
    June 2021
    April 2021
    March 2021
    November 2020
    August 2020
    April 2020
    October 2019
    May 2019
    April 2019
    December 2018
    October 2018
    September 2018
    August 2018
    June 2018
    May 2018
    April 2018
    March 2018
    January 2018
    November 2017
    October 2017
    August 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    September 2016
    August 2016
    July 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    October 2015
    July 2015
    June 2015
    March 2015
    February 2015
    January 2015
    November 2014
    June 2014
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013

    Categories

    All
    Education
    Marine Biology
    Outreach
    Photography
    Science
    Scuba

Proudly powered by Weebly