[Coral-List] Salinity and temp tolerance in seagrasses

[Jeremy Sofonia]

Thank you David,

And thank you to the List for the great response and guidance...

As what I hope will be a 'worst-case' approach, we're going to work with
setting the potential 'zone of effect' at +1C above ambient (approx. 36C)
and 50ppt with the spatial extent estimated using numerical modelling.

Running with these numbers the area of potential impacts is probably
larger than some involved in the project may have initially anticipated. 
Given the lack of site-specific data, however, I feel moving forward
conservatively is the best approach and if the actual impacts are less...
well... then it's a better outcome than the other way round.

David - you raise an interesting point about the effect of differentials
in the winter period.  I will try to incorporate this in our call for
regular monitoring prior to, during, and post project development.  As
with many other aspects regarding the potential environmental impacts, the
level of monitoring will ultimately be decided by the local regulatory
authorities.

Thank you again everyone for your time and thoughts. I'll post again if
anything interesting comes from this...

Kind regards,

Jeremy





On Tue, October 7, 2008 12:03, Medio, David wrote:
> Jeremy
>
>
>
> I have observed healthy seagrass beds in Qatar, UAE (Abu Dhabi, Umm al
> Quwain, RAK etc) and agree with comments already posted. Seagrasses in
> this part of the world have developed tolerance levels to high salinity
> (up to 50ppt in some cases) and temperature, the latter not so much the
> highs but the range (low teens to mid forties in sheltered shallow
> bays).
>
>
>
> The crucial issue will be the Delta T in the winter more than the summer
> given that you may have a significant differential then. Also with blade
> shedding in winter, seagrasses may be more vulnerable to large T
> differentials.
>
>
>
> David
>
>
>
> Dr David Medio
> Principal Environmental Scientist
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