[Coral-List] Assessing reef health through fish ID

Andrew Halford andrew.halford at gmail.com
Wed Mar 18 22:43:01 EDT 2015


You will always get differing opinions about what are the best species to
survey. At the end of the day you are just choosing "proxies" to keep an
eye on reef health. The trick is to focus on a small group of species so
that it will be far easier to train people and maintain the counts over
time. Power in monitoring programs comes from the time series not from the
number of species you count. How many species you count is far less
important than doing it well and doing it for an extended period.

As for which species, you have been given some worthwhile examples such as
butterfly fish which are easy to identify and count. What you will need to
consider however, is that you will not get good counts across all fish
species using one methodology. For example, trying to count larger, more
mobile species such as the larger Lutjanids, Lethrinids and Serranids on 30
m x 2m or 5m transects or 7.5m radius point counts will likely produce
zero-inflated counts which will give you very poor power to detect

If your primary interest is to track reef fish community structure through
time then counting a suite of species on your transects will give you a
perfectly good signal for this. However if you are also interested in
looking at species that are targeted by fishing and you wish to compare
counts inside and out of protected areas then you will have to consider
timed swims or larger transects as a means to obtaining better abundance
estimates of the larger more mobile species that are typically targeted
through fishing.

Melita Samoilys is a perfect local contact for deciding what species to
monitor and would perhaps enable you to build on their work rather than
replicate it . And I would also point you to the extensive body of research
published by Gary Russ and Angel Alcala which has used visual census counts
over many years to provide a wonderful picture of the dynamics of fish
communities subjected to fishing and protection over an extended period of

Some references to get you started would be..

Russ & Alcala (1996) Marine reserves: rates and patterns of recovery and
decline of large predatory fish. Ecological Applications 6 (3): 947-961

Russ & Alcala (2004) Marine reserves: long-term protection is required for
full recovery of predatory fish populations. Oecologia 138 (4): 622-627

If you can't access these papers drop me an email and I can help.



Andrew Halford PhD

Research Scientist, Monitoring (Kimberley Marine Parks)

Dept. Parks & Wildlife

17 Dick Perry Ave, Kensington WA 6151

(Ph): +61 (0) 8 9219 9795; (mob): +61 (0) 468 419473

On 18 March 2015 at 13:47, David Obura <dobura at cordioea.net> wrote:

> Hi Gus,
> For community-based fish/fisheries work in Mozambique there are a number
> of programs already in place that would be good for you to connect with.
> Most directly, I'd put you in touch with Dr. Melita Samoilys (CORDIO) and
> Dr. Nick Hill (Zoological Society of London) who are working on such issues
> in Cabo Delgado in the north. They can give you information on
> national/local partners as well in Mozambique, as the the government has
> had a small scale fisheries programme running for over 20 years that any
> new initiatives should ensure to build on/collaborate with.
> Mozambique has a strong focus on development of CCPs (local fishery
> organizations) as the node for interactions with community fishers.  If by
> volunteers you mean divers and tourists, then things might be quite
> different. But Melita and Nick can assist with the questions you ask ...
> regards,
> David Obura
> CORDIO East Africa
> #9 Kibaki Flats, Kenyatta Beach, Bamburi Beach
> P.O.BOX 10135 Mombasa 80101, Kenya
> www.cordioea.net ; Email: dobura at cordioea.net; davidobura at gmail.com
> Mobile: +254-715 067417; skype dobura; Twitter @dobura
> >
> >
> > ------------------------------
> >
> > Message: 3
> > Date: Tue, 17 Mar 2015 09:17:45 +0000
> > From: Gus Fordyce <GusFordyce.2011 at my.bristol.ac.uk>
> > Subject: [Coral-List] Assessing reef health through fish ID
> > To: coral-list at coral.aoml.noaa.gov
> > Message-ID:
> >       <
> CAN_vqstRhpzOeYeeOPnMr+asaEVU3Uc9VA5_ratVOesP85LbbA at mail.gmail.com>
> > Content-Type: text/plain; charset=UTF-8
> >
> > Dear coral-listers,
> >
> > I'm about to start a position in Mozambique as scientific coordinator
> for a
> > marine conservation volunteer program, and could use some guidance. One
> of
> > my key roles upon arriving out there will be to design a fish ID training
> > program that will standardize the way volunteers collect data on species
> > abundances and locations, all with the aim of assessing the changing
> health
> > of the reefs without introducing volunteer bias.
> >
> > What species (or even taxa) are sensitive to changes in reef health and
> so
> > can be a good measure of the health of the reef? My immediate thought was
> > to look near the top end of the food chain, but I also want volunteers to
> > have a good chance of seeing them so we can build a large dataset and
> they
> > can have a good time!
> >
> > Advice on successful training techniques would also be helpful.
> > Any and all help is much appreciated,
> >
> > Cheers,
> > Gus Fordyce
> >
> > MSci Biology student
> > University of Bristol
> >
> >
> > ------------------------------
> >
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Andrew Halford Ph.D
Research Scientist (Kimberley Marine Parks)|  Adjunct Research Scientist
(Curtin University)
Dept. Parks and Wildlife
Western Australia

Ph: +61 8 9219 9795
Mobile: +61 (0) 468 419 473

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