How seaweed has been misleading scientists about reef health

Date:
May 4, 2023
Source:
University of British Columbia
Summary:
For decades, scientists have used the amount of seaweed at
the ocean's surface as a proxy for the health of coral reefs
below. However, a new global study of more than 1,200 marine
locations over a 16-year period reveals that this approach has
been misleading -- and may even have hidden signs of reef stress.


Facebook Twitter Pinterest LinkedIN Email

==========================================================================
FULL STORY ==========================================================================
For decades, scientists have looked to seaweed as an indicator of the
health of coral reefs lying underneath.

But what if the seaweed was misleading them? New UBC research reveals
it was, and scientists need new ways to determine whether human activity
is harming a particular reef.

"This is especially critical today, given that reefs globally are
threatened by climate-driven stressors," said Dr. Sara Cannon, a
postdoctoral fellow at the UBC Institute for the Oceans and Fisheries
and the study's lead author.

Local species behave differently Seaweed belongs to a group of organisms
called macroalgae. Macroalgae at the ocean's surface has long served
as a proxy for reef health, because it is relatively quick and easy to
measure. Since the 1970s, scientists have assumed that local human impacts increase macroalgae while simultaneously damaging underlying reefs.

However, the study just published in Global Change Biology looked at data
from over 1,200 sites in the Indian and Pacific Oceans over a 16-year
period and revealed that this approach is misleading and may even have
hidden signs of reef stress.

For example, macroalgae coverage depends heavily on the species growing in
a particular area. Sargassum is less likely to grow in water contaminated
by agricultural runoff, but Halimeda will thrive. In both cases, a reef
will suffer.

The global research team concluded that using macroalgae coverage as
an indicator of local human impacts can actually obscure how much our
actions are harming reefs, and cause scientists to misidentify the reefs
most in need of intervention.

* RELATED_TOPICS
o Plants_&_Animals
# Nature # Marine_Biology # Extinction # New_Species
o Earth_&_Climate
# Coral_Reefs # Ecology # Global_Warming #
Environmental_Awareness
* RELATED_TERMS
o Coral_reef o Artificial_reef o
Temperature_record_of_the_past_1000_years o Great_Barrier_Reef
o Coral o Coral_bleaching o Paleoclimatology o Dinoflagellate

========================================================================== Story Source: Materials provided by University_of_British_Columbia. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Sara E. Cannon, Simon D. Donner, Angela Liu, Pedro C. Gonza'lez
Espinosa,
Andrew H. Baird, Julia K. Baum, Andrew G. Bauman, Maria Beger,
Cassandra E. Benkwitt, Matthew J. Birt, Yannick Chancerelle, Joshua
E. Cinner, Nicole L. Crane, Vianney Denis, Martial Depczynski,
Nur Fadli, Douglas Fenner, Christopher J. Fulton, Yimnang
Golbuu, Nicholas A. J. Graham, James Guest, Hugo B. Harrison,
Jean‐Paul A. Hobbs, Andrew S. Hoey, Thomas H. Holmes, Peter
Houk, Fraser A. Januchowski‐Hartley, Jamaluddin Jompa,
Chao‐Yang Kuo, Gino Valentino Limmon, Yuting V.

Lin, Timothy R. McClanahan, Dominic Muenzel, Michelle J. Paddack,
Serge Planes, Morgan S. Pratchett, Ben Radford, James Davis Reimer,
Zoe T.

Richards, Claire L. Ross, John Rulmal, Brigitte Sommer, Gareth J.

Williams, Shaun K. Wilson. Macroalgae exhibit diverse responses
to human disturbances on coral reefs. Global Change Biology, 2023;
DOI: 10.1111/ gcb.16694 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/05/230504121006.htm

--- up 1 year, 9 weeks, 3 days, 10 hours, 52 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)