TY - JOUR
T1 - The population biology of the thornback ray, Raja clavata in Caernarfon Bay, north Wales
AU - Whittamore, J. M.
AU - McCarthy, I. D.
PY - 2005/10
Y1 - 2005/10
N2 - Amid concern about the status of skates and rays in Welsh waters the present work set out to provide up-to-date information on the population biology of Raja clavata in Caernarfon Bay. The von Bertalanffy growth parameters were L∞=100.9 cm, k=0.18 y-1 and t0=-0.95 y for males; and L∞=117.6 cm, k=0.16 y-1 and t 0=-0.7 y for females. Male R. clavata reached 50% maturity at 58.8 cm and 3.9 y, which was smaller and younger than females (L50 and A50 were 70.5 cm and 5.3 y, respectively). Although previously over-exploited, the present estimate of total mortality (Z) was 0.48-0.49 y -1 which, in terms of replacement mortality (calculated as 0.7 y -1), suggests no immediate prospect of recruitment failure for R. clavata in Caernarfon Bay. The potential for the recovery of a depleted population is discussed in relation to the Allee effect.
AB - Amid concern about the status of skates and rays in Welsh waters the present work set out to provide up-to-date information on the population biology of Raja clavata in Caernarfon Bay. The von Bertalanffy growth parameters were L∞=100.9 cm, k=0.18 y-1 and t0=-0.95 y for males; and L∞=117.6 cm, k=0.16 y-1 and t 0=-0.7 y for females. Male R. clavata reached 50% maturity at 58.8 cm and 3.9 y, which was smaller and younger than females (L50 and A50 were 70.5 cm and 5.3 y, respectively). Although previously over-exploited, the present estimate of total mortality (Z) was 0.48-0.49 y -1 which, in terms of replacement mortality (calculated as 0.7 y -1), suggests no immediate prospect of recruitment failure for R. clavata in Caernarfon Bay. The potential for the recovery of a depleted population is discussed in relation to the Allee effect.
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U2 - 10.1017/S0025315405012130
DO - 10.1017/S0025315405012130
M3 - Article
AN - SCOPUS:26444545517
SN - 0025-3154
VL - 85
SP - 1089
EP - 1094
JO - Journal of the Marine Biological Association of the United Kingdom
JF - Journal of the Marine Biological Association of the United Kingdom
IS - 5
ER -