Soft-sediment biogeochemistry is influenced by the bioturbation activity of benthic invertebrates. We investigated whether effect two macrobenthos bioturbators, Limecola balthica and Hediste diversicolor , on sediment oxygen uptake can be described allometric principles metabolic scaling with animal body size population biomass. Microcosms containing reconstructed populations to control density...

Bioturbation is known to stimulate microbial communities, especially in macrofaunal burrows where the abundance and activities of bacteria are increased. Until now, these microbial communities have been poorly characterized and an important ecological question remains: do burrow walls harbor similar or specific communities compared with anoxic and surface sediments? The bacterial community stru...

The aim of this work was to quantify the intensity of sediment mixing induced by the gallery-diffusor (functional bioturbation group) Hediste diversicolor as a function of density, using particles tracers (luminophores). In order to assess the impact of density on sediment reworking, a 1-D model was used to obtain sediment reworking coefficients such as Db (biodiffusion-like) and r (biotranspor...

The feeding ecology of Nereis diversicolor (O. F. Müller, 1776) (Annelida: Polychaeta) was studied over 14 months at three estuarine-lagoon systems of the Southwest coast of Portugal (Odeceixe, Aljezur and Carrapateira). The analyses of digestive tract revealed that diet change according to site, period of the year and individual sizes. There are no differences in the digestive contents between...

Nereis diversicolor is a widely distributed estuarine polychaete worm that is particularly abundant in the mid to upper parts of estuaries. Laboratory annular flumes were used to study the effects of N. diversicolor density (0 [control], 100, 300, 1000, 3000 individuals m–2) on erodability of cohesive muddy sediments. At the highest densities (1000 and 3000 ind. m–2) there was evidence of activ...

Since 2002, an increased number of northern sea otters (Enhydra lutris kenyoni) from southcentral Alaska have been reported to be dying due to endocarditis and/or septicemia with infection by Streptococcus infantarius subsp. coli. Bartonella spp. DNA was also detected in northern sea otters as part of mortality investigations during this unusual mortality event (UME) in Kachemak Bay, Alaska. To...

This is the first host record of Gymnophallus choledochus metacercariae infecting the polychaete Diopatra neapolitana in the Aveiro estuary (Portugal). The metacercariae were found unencysted, and their morphology is similar to that presented by metacercariae harbored by Nereis diversicolor and Cerastoderma edule, although they are larger in size. In D. neapolitana, the prevalence and mean inte...