[MARMAM] New paper: Quantifying cetacean prey consumption ...

C.Saavedra camilo.saavedra at vi.ieo.es
Thu Oct 23 14:04:13 PDT 2014


Dear all,

We are pleased to announce the publication of the following article:
"Quantifying the predation on sardine and hake by cetaceans in the 
Atlantic waters of the Iberian peninsula"

Which had been already published on-line, but recently has been also 
published on paper format in "Deep Sea Research Part II: Topical Studies 
in Oceanography"

The citation and the abstract is bellow:

Santos, M.B., Saavedra, C., Pierce, G. P. (2014). Quantifying the 
predation on sardine and hake by cetaceans in the Atlantic waters of the 
Iberian peninsula. Deep Sea Research Part II: Topical Studies in 
Oceanography, 106: 232-244.

Construction of ecosystem models requires detailed information on 
trophic interactions which may not be readily available, especially for 
top predators such as cetaceans. Such information can also be useful to 
estimate natural mortality (M) for fish stock assessments and to 
evaluate the potential for competition between cetaceans and fisheries. 
In the present paper we provide estimates and confidence limits, taking 
into account sampling error, for consumption of fish by the four most 
common cetaceans along the Atlantic coast of the Iberian Peninsula, 
while highlighting the uncertainties and biases inherent in the 
information presently available on energy requirements, diet and 
population size. We estimated that common dolphins (Delphinus delphis) 
consume around 6800 (95% CI, 4871–9476) tons of sardine (Sardina 
pilchardus), 8800 (6195–12,647) tons of gadids, 1100 (721–1662) tons of 
hake (Merluccius merluccius) and 1900 (1222–2752) tons of scads 
(Trachurus sp.) annually. For striped dolphins (Stenella coeruleoalba), 
prey consumed were 900 (196–2661) tons of sardine, 6200 (3448–11,129) 
tons of gadids, 200 (11–504) tons of hake and 1600 (0–5318) tons of 
scads. Estimated amounts taken by harbour porpoises (Phocoena phocoena) 
and bottlenose dolphins (Tursiops truncatus) are much lower, reflecting 
their low abundance in the area. Cetacean predation on sardine 
represents 2–8% of the current M value, indicating that cetaceans 
probably have little influence on sardine population dynamics. For the 
southern hake stock, estimated average removal by cetaceans often 
exceeds M. While this may indicate that both M and the consumption 
estimates for hake require revision it also suggests that cetaceans 
could have a more significant impact on hake populations. Different 
approaches to estimation of energy requirements of cetaceans can result 
in figures that differ by at least a factor of 2. The lack of good 
estimates of field metabolic rate for most species probably represents 
the most serious barrier to reliably quantifying the role of cetaceans 
in the ecosystem.

The article can be found at:
http://www.sciencedirect.com/science/article/pii/S0967064513003810

If you can't download it from ScienceDirect, you can look for it in 
Researchgate.com or request a copy to my email: camilo.saavedra at vi.ieo.es

Best Wishes,
C.Saavedra


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