Decreased iron levels in seawater make mussels loosen their grip

Date:
July 29, 2020
Source:
American Chemical Society
Summary:
Mussels secrete sticky plaques that help them attach to wet
surfaces, such as rocks on the beach. These adhesive structures
are rich in iron, which is thought to help make the attachments
strong yet flexible. Now, researchers have shown that mussels
form weaker attachments in iron- deficient seawater, revealing a
possible consequence of altered iron bioavailability in oceans.



FULL STORY ========================================================================== Mussels secrete sticky plaques that help them attach to wet surfaces,
such as rocks on the beach. These adhesive structures are rich in iron,
which is thought to help make the attachments strong yet flexible. Now, researchers reporting in Environmental Science & Technology have shown
that mussels form weaker attachments in iron-deficient seawater, revealing
a possible consequence of altered iron bioavailability in oceans.


==========================================================================
As oceans become more acidic in a changing climate, iron dissolves and is
less bioavailable to filter feeders, such as mussels, that strain iron particles from seawater. In mussels, iron helps cross-link proteins in
the sticky plaques that attach to surfaces and adds mechanical toughness
to the hair-like threads that link the plaque to the mollusk's inner
tissues. Jonathan Wilker and colleagues at Purdue University wondered
how mussels' ability to adhere to surfaces would be affected by changing
iron levels in seawater.

To find out, the researchers cultured mussels in artificial seawater
containing lower, normal and higher iron levels. The researchers grew
the mussels in each water condition for three days, during which the
creatures attached to aluminum plates. Then, the researchers cut off the threads near the shell and pulled upward on them, measuring the force
needed to remove the plaque from the plate.

As the concentration of iron in the water increased, so did the plaque's stickiness, except for the highest iron level, at which adhesion slightly decreased. The team also observed that the plaques became smaller and
darker as the iron concentration increased, and the porous microstructure
of the plaques became more pronounced. This study is the first to examine
how changing iron levels affect the performance of a biological material
in a whole animal, the researchers say.


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


========================================================================== Journal Reference:
1. Natalie A. Hamada, Christopher Gilpin, Jonathan
J. Wilker. Availability
of Environmental Iron Influences the Performance of Biological
Adhesives Produced by Blue Mussels. Environmental Science &
Technology, 2020; DOI: 10.1021/acs.est.0c02392 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/07/200729114832.htm

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