Detached aquaculture buoys in the SE Pacific: potential dispersal vehicles for associated organisms

Abstract

Throughout the world's oceans a wide variety of floating plastics are found, among which buoys stand out for their high floatability and diversity and abundance of associated organisms. Between 2001 and 2005, we conducted 25 ship surveys in the Bay System of Coquimbo (BSC), during which we registered 34 detached buoys floating between 1 and 45 km from the coast. The objective of this study was to infer the possible origin of these buoys, identify the associated biota and characterize their biological traits. Short-term drift experiments (30 min) showed that buoys without rope responded primarily to the velocity and direction of the wind, while buoys with ropes (3 m length) followed surface currents. Using the wind velocity and direction during the 12 h before capture of the detached buoys, we estimated the hypothetical trajectories of these buoys during that time period. Results indicated that most buoys originated from aquaculture facilities in the BSC. A total of 134 different species from 14 phyla was found on 18 anchored (91 species) and 22 detached (116 species) buoys sampled. Community composition was similar among buoys -54% of all species were common for anchored and detached buoys -but a higher number of rare species occurred on detached buoys. Buoys do not seem to lose but rather gain organisms after detachment. The most common functional groups on these buoys were mobile species, suspension-feeders and species with sexual reproduction, separate sexes, internal fertilization and direct or very short larval development. Fouling communities on detached buoys were mostly in advanced successional stages, comprising diverse species (including several non-indigenous species) adapted to the conditions at the sea surface. These results suggest that floating buoys may transport associated species over extensive distances, thereby also contributing to the spread of non-indigenous species.

Long-distance dispersal, low connectivity and molecular evidence of a new cryptic species in the obligate rafter Caprella andreae Mayer, 1890 (Crustacea: Amphipoda: Caprellidae)

“…Dispersal mechanisms of caprellid species include mainly rafting (both natural and artificial substrata) (Caine 1980). They have been found to survive transport in ballast tanks (Carlton 1985) as well as dispersing over large distances as part of the fouling communities of sea-going vessels Astudillo et al 2009). In fact, the global distribution and introduction pathways of some invasive caprellid species can be attributed to these vectors (Caprella californica: AMBS 2002; Caprella mutica: Takeuchi and Sawamoto 1998;Ashton 2006;Ashton et al 2008;Caprella scaura: Krapp-Schickel et al 2006;Martí-nez and Adarraga 2008;Guerra-García et al 2011).…”

Spatio-temporal distribution of floating objects in the German Bight (North Sea)

“…seaweed beds, rivers, fishery and shipping activity), (ii) temporal supply dynamics (e.g. annual growth seasons for vegetation or river runoff for wood and litter) (Kingsford, 1992;Johansen, 1999;Hirata et al, 2001;Moore et al, 2002), (iii) their floating potential at the sea surface (Barnes and Fraser, 2003;Vandendriessche et al, 2007;Rothäusler et al, 2009), and (iv) winds, currents and other hydrographic features such as frontal systems that drive dispersal, accumulation and sink processes (Valle-Levinson et al, 2006;Komatsu et al, 2007;Pichel et al 2007;Astudillo et al, 2009;Martinez et al, 2009). In the German Bight floating wood and anthropogenic debris come through the major rivers, and supply may vary during the year due to seasonally varying river runoff.…”

Ecología de invasiones marinas en Chile continental: ¿Qué sabemos y que nos falta por saber?

“…En el norte de Chile se ha observado el importante rol de boyas a la deriva, como mecanismo efectivo de dispersión a larga distancia para algunos invertebrados introducidos como Ciona robusta o Bugula neritina (Astudillo et al 2009). En el sur de Chile, Manríquez et al (2014) han estudiado las comunidades incrustantes en pilotes de muelles en sectores con alto tráfico marítimo.…”

“…Esto ha llevado a que los catastros de especies exóticas, incluso los más actualizados (e.g., LIB 2016) 3 infieran la distribución de estas especies en base a revisiones de artículos publicados o bien muestras conservadas en herbarios y/o museos. Si bien las colecciones de museos han sido reconocidas como herramientas eficaces para el estudio de la biodiversidad en general (Ramírez 2001) e invasiones biológicas en particular (Fuentes et al 2013), el uso exclusivo de este tipo de información puede sesgar la información hacia zonas más estudiadas, lo que presenta una desventaja frente a muestreos in situ.…”