[Coral-List] FW: Loss of reef biodiversity - any recent data?

[Héctor Reyes Bonilla]

Saludos a todos.

To talk about "extinction" (either local or absolute) is tricky because it
is quite hard to demonstrate that something is not there (ask any
philosopher). And for logistic reasons, in the sea the problem becomes even
more complex.

I have not read Zoe Richards´ paper yet (sorry about that), but anyway for
those interested in the subject, I would recommend to take a look at the
study of  del Monte et al. (Fish and Fisheries, 8: 107. 2007) on marine
extinctions. We discuss how difficult it is to determine if a marine
species has disappeared from an area, and show that in many (actually
most...) cases those extirpations are temporary, as the species eventually
returns (probably because of metapopulation dynamics). I think that
although not so recent, the paper may be helpful nowadays when analyzing
anthropogenic impacts on marine biodiversity.

Hector Reyes



El mié, 1 sept 2021 a las 9:20, David Blakeway via Coral-List (<
coral-list at coral.aoml.noaa.gov>) escribió:

> Hi Peter, Zoe, Austin,
>
> It does seem a bad situation. Losing diversity must be worse than losing
> cover (not that they are independent).
> But, especially in Zoe's Lizard Island example, it would be good to have
> some sort of null model to compare the observed changes against. I mean a
> theoretical population in which some proportion of species are
> intermittently present and absent. If we time-sampled that population we
> would record multiple local extinctions and new records, even if there were
> no long term trend in diversity (that may be what your 'observed vs.
> expected' tests are doing Zoe?). It is interesting from that perspective
> that you found 51 new records in addition to the 28 + 31 losses. Though I
> guess some of those new records may have been present all along.
> I don't mean to imply that I doubt your conclusion that this could be a
> real, anthropogenic, negative trend in diversity at Lizard Island. It seems
> parsimonious, and the 2011-2017 loss is clear in Fig 1a & b. And I know you
> will have already considered all these points. I am just trying to
> understand what patterns *could* occur if (industrialized) humanity hadn't
> appeared.
>
> Austin, could you share some of the research questions you would like to
> see addressed? I feel they would likely provide some perspective and focus
> for us all.
>
> Regards,
> David
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> https://coral.aoml.noaa.gov/mailman/listinfo/coral-list
>


-- 
Héctor Reyes Bonilla
Departamento Académico de Ciencias Marinas y Costeras
Universidad Autónoma de Baja California Sur
Carretera al sur km 5.5. Col. El Mezquitito
La Paz, B.C.S., C.P. 23080.
Tel. (52-612) 123-8800, ext. 4814
Fax (52-612) 123-8819.

-- 
El aviso de la privacidad de este correo se puede consultar en 
www.uabcs.mx/transparencia/Privacidad.html 
<http://www.uabcs.mx/transparencia/Privacidad.html>