MEPS 546:113-122 (2016)  -  DOI: https://doi.org/10.3354/meps11658

ABSTRACT: Transplantation of the protected Mediterranean fan mussel Pinna nobilis is assessed as a potential conservation action. A pilot study in the marine Lake Vouliagmeni (Greece) showed variable success of transplantation, due to spatial variation in mortality rates: in a shallow (4 m) and easily accessible area, mortality of 20 transplanted individuals of various size classes was 100% in 72 d, mainly because of poaching, while in a deeper (12 m), less-accessible area, mortality was only 20%, unrelated to poaching and affecting mainly small individuals (all transplants of the first size class were found dead in both shallow and deep areas). In a subsequent transplantation experiment of 45 large fan mussels, transplanted from a depth of 4 m to a depth of 12 m, growth and mortality rates were monitored for 5 yr. Survival after 5 yr was very high (95.6%), and growth rates did not differ to those of non-transplanted individuals at the same depth (control). A metapopulation, time-invariant, stage-classified matrix model was used to assess the effect on the population of possible massive transplantation of fan mussels from the shallow waters of the lake (suffering from poaching) to the deeper protected areas. Several scenarios about transplantation effort were analysed. Massive transplantation would result in a substantial increase of the average life expectancy, expected lifetime offspring production, population growth rates, and abundance, at a reasonable estimated cost. Hence, in areas where fan mussels suffer from high mortality, transplantation of individuals older than the 1st age class appears to be an effective action to protect local populations.

KEY WORDS: Pinna nobilis · Transplantation · Conservation · Mortality · Growth · Population dynamics · Matrix population model · Monitoring