Jellyfish blooms result in a major microbial respiratory sink of carbon in marine systems

Abstract

Jellyfish blooms occur in many estuarine and coastal regions and may be increasing in their magnitude and extent worldwide. Voracious jellyfish predation impacts food webs by converting large quantities of carbon (C), fixed by primary producers and consumed by secondary producers, into gelatinous biomass, which restricts C transfer to higher trophic levels because jellyfish are not readily consumed by other predators. In addition, jellyfish release colloidal and dissolved organic matter (jelly-DOM), and could further influence the functioning of coastal systems by altering microbial nutrient and DOM pathways, yet the links between jellyfish and bacterioplankton metabolism and community structure are unknown. Here we report that jellyfish released substantial quantities of extremely labile C-rich DOM, relative to nitrogen (25.6 ± 31.6 C:1N), which was quickly metabolized by bacterioplankton at uptake rates two to six times that of bulk DOM pools. When jelly-DOM was consumed it was shunted toward bacterial respiration rather than production, significantly reducing bacterial growth efficiencies by 10% to 15%. Jelly-DOM also favored the rapid growth and dominance of specific bacterial phylogenetic groups (primarily γ-proteobacteria) that were rare in ambient waters, implying that jelly-DOM was channeled through a small component of the in situ microbial assemblage and thus induced large changes in community composition. Our findings suggest major shifts in microbial structure and function associated with jellyfish blooms, and a large detour of C toward bacterial CO 2 production and away from higher trophic levels. These results further suggest fundamental transformations in the biogeochemical functioning and biological structure of food webs associated with jellyfish blooms.biogeochemical cycling | jelly carbon shunt | fisheries production

Benthic scavengers and predators of jellyfish, material for a review

“…All these authors described the events as feeding frenzies, leading to the (near-) annihilation of the jellyfishes. This and my list of benthic invertebrate predators and scavengers (Table 1) contradicts the notion that jellyfish are not readily consumed by other predators (Condon et al 2011). Quite the opposite may occur when jellyfish hit the coast or the sea floor.…”

“…Nevertheless, jellyfish continue to be depicted occasionally (see Arai 2005 for examples) as dead ends in the food chains of the sea and/or as a rare source of food for predators (e.g. Condon et al 2011), despite an increasing number of species of fishes (Redeke 1911, Luttenberger 1981, Gorelova & Grudtsev 1986, Kelley 1987, Ates 1988, Arai 1988, Zann 1988: 208, Cerqueira & Haimovici 1990, Hall 1992, Harbison 1993, Massuti et al 1998, Purcell & Arai 2001, Bonaldo et al 2004, Arai 2005, Orsi Relini et al 2010a, Orsi Relini et al 2010b, Chaves et al 2010, Thaler 2012, Cardona et al 2012, Milisenda et al 2014, Battaglia et al 2014, Sweetman et al 2014, Dias & Almeida 2015, birds, reptiles and mammals (Dathe 1989, Ates 1991, Gronert 1992, Shiomi & Ogi 1992, Bell 1996, Zonfrillo 1997, Peglow 1998, Corsi 2000, Arai 2005, Suazo 2008, Cardona et al 2012, Jarman et al 2013, Melville 2013, Jones & Seminoff 2013, other cnidarians and ctenophores …”

Predictable and efficient carbon sequestration in the North Pacific Ocean supported by symbiotic nitrogen fixation

“…Since the original conceptualization of the BCP, numerous refinements and elaborations have appeared to accommodate new discoveries and improved mechanistic understanding (10,(21)(22)(23). The so-called "N 2 -primed prokaryotic carbon pump" describes the impact that N 2 fixation can have on particle export processes in NO 3 − -limited, oligotrophic ecosystems, including enhanced carbon sequestration via elevated C/P ratios (10).…”

The influence of invasive jellyfish blooms on the aquatic microbiome in a coastal lagoon (Varano, SE Italy) detected by an Illumina-based deep sequencing strategy

“…The protein-rich decay jellyfish biomass and the mucous excretion of living jellyfish also are readily assimilated by jellyfish-associated and free-living bacteria and can cause rapid shifts in microbiome structure and organization (Tinta et al 2010(Tinta et al , 2012. The bacterial use of jelly-DOM could lead to the repackaging of gelatinous organic carbon and its reincorporation into the food web (Condon et al 2011). In addition, the decay of gelatinous biomass (jellyfalls) following bloom events leads to the rapid and massive release in the water column of dissolved inorganic and organic compounds (Pitt et al 2009).…”