The origin of sedimenting detrital matter in a coastal system

Lundsgaard, Claus; Olesen, Michael

doi:10.4319/lo.1997.42.5.1001

Cited by 25 publications

(17 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is the lowest value reported. By comparison, in the Kattegat (Lundsgaard and Olesen 1997), in the Norwegian Sea (Bathmann et al 1987), and on the Japanese coast (Sasaki et al 1988), fecal pellets contributed to 4-20% of particulate organic carbon sedimentation. Apparently, the special characteristics of the coastal northern Baltic Sea, i.e., steep hydrographical stratification, potential dominance of athecate flagellates and protozoans in the diet of copepods, and especially the dominance of small copepods, all make this area an extreme case in this respect.…”

Section: Discussionmentioning

confidence: 99%

Sedimentation of copepod fecal material in the coastal northern Baltic Sea: Where did all the pellets go?

Viitasalo

Rosenberg²,

Heiskanen

et al. 1999

Limnology & Oceanography

View full text Add to dashboard Cite

We investigated the sedimentation of copepod fecal pellets in three different sea areas representing a sheltered bay, an archipelago area, and the open sea on the southwestern coast of Finland in the northern Baltic Sea. Fecal carbon sedimentation was always Ͻ0.05% of the total sedimentation of particulate organic carbon, whereas the fecal carbon production (estimated from copepod abundance, assuming production rate of 10 pellets copepod Ϫ1 d Ϫ1) contributed to 4-17% of particulate organic carbon sedimentation. Thus, Ͼ99% of copepod fecal material was remineralized within the mixed water layer (0-20 m). However, in the area and season dominated by the large calanoid copepod Limnocalanus macrurus (bay station in spring), fecal carbon sedimentation was an order of magnitude higher than at the other two stations. From June onwards, when the bay station was dominated by cyclopoids, the situation changed: the fecal carbon sedimentation remained 30% lower in the bay than in the archipelago, although the fecal carbon production was estimated to be 2 times higher in the bay. Furthermore, pellet fragmentation (percentage of broken pellets of total fecal carbon sedimentation) was highest in spring and autumn at all areas and increased towards the open sea, being 27%, 45%, and 61% at the bay, archipelago, and open sea stations, respectively. This gradation was probably due to more intense turbulence and water column mixing in the open sea, resulting in more efficient loosening and breakup of pellets. The overall contribution of copepod feces to vertical carbon export in the northern Baltic Sea appears to be small, but seasonal and spatial variations in hydrography and mesozooplankton community structure significantly affect the fecal pellet sedimentation rates.

show abstract

Section: Discussionmentioning

confidence: 99%

Sedimentation of copepod fecal material in the coastal northern Baltic Sea: Where did all the pellets go?

Viitasalo

Rosenberg²,

Heiskanen

et al. 1999

Limnology & Oceanography

View full text Add to dashboard Cite

show abstract

“…In Disko Bay, heterotrophic dinoflagellates were estimated to graze 7-18% of the diatom bloom. Using the same data for the Kattegat as presented in this paper, Lundsgaard and Olesen (1997) suggested that heterotrophic dinoflagellate ingestion was 21% of the spring bloom primary production. By comparison, the potential grazing of copepods during the same period was 20 to Ͼ100% (Disko; Madsen et al 2001) and 8% (Kattegat; Lundsgaard and Olesen 1997) of the primary production.…”

Section: ϫ2mentioning

confidence: 99%

The trophic role of marine pelagic ciliates and heterotrophic dinoflagellates in arctic and temperate coastal ecosystems: A cross‐latitude comparison

Levinsen¹,

Nielsen²

2002

Limnology & Oceanography

137

View full text Add to dashboard Cite

We compared seasonal studies of ciliates and heterotrophic dinoflagellates conducted in Disko Bay (West Greenland, ϳ69ЊN) and the Kattegat (Denmark, ϳ56ЊN). In both systems, ciliates and heterotrophic dinoflagellates were important components of the plankton. Their biomass was minute in the winter (October to April) in Disko Bay compared to the Kattegat, but from May to August/September, the biomass and composition of the ciliate and heterotrophic dinoflagellate assemblages were similar in the two systems. The seasonal biomass pattern was unimodal and bimodal for Disko Bay and the Kattegat, respectively. To evaluate top-down versus bottom-up control, experimentally derived maximum estimates of protozooplankton growth rates and copepod predation capacities from the study sites were applied to biomass data. This analysis showed that the effect of copepods was significant but that ciliates and heterotrophic dinoflagellates could effectively exploit prey during periods when top-down pressure was relaxed. In Disko Bay, a high copepod biomass in spring is primarily caused by migration of an overwintering copepod population from deep waters into the photic zone prior to the spring bloom. We suggest that ''regulation windows'' for the protozooplankton are present even during the spring bloom when copepods occur at their peak levels because of food saturation. Bottom-up regulation occurred during the winter and occasionally when copepod predation pressure relaxed, but it was difficult to separate food limitation from the effect of temperature. Multiple regression analysis supports the notion that ciliate and heterotrophic dinoflagellate biomass changed seasonally according to both top-down and bottom-up regulation, as well as to temperature control. Protozooplankton growth estimates were also used to calculate the fraction of primary production processed by the ciliates and heterotrophic dinoflagellates. When assuming complete algivory, 32-55% and 20-60% of the annual primary production was consumed by ciliates in Disko Bay and the Kattegat, respectively. Furthermore, because heterotrophic dinoflagellates were found to be as important grazers as ciliates in both systems, it was concluded that protozooplankton at high latitudes are also important in the cycling of primary production and should be considered if carbon and nutrient cycling in these systems is to be understood.During the past decade it has been shown that ciliates and heterotrophic dinoflagellates are abundant in arctic marine waters; these protists have higher growth capacities than copepods from the genus Calanus, which traditionally have been considered the principal grazers associated with high latitudes (Andersen 1988;Nielsen and Hansen 1995;Hansen et al. 1996;Sherr et al. 1997;Levinsen et al. 2000a). Furthermore, adult and nauplii of the Calanus species have been shown to preferentially feed on ciliates and dinoflagellates (Barthel 1988;Ohman and Runge 1994; Levinsen et al. 1 To whom correspondence should be addressed. Present address: Unive...

show abstract

“…Although fecal pellet in some cases constitute a significant fraction of the sedimenting organic carbon , Landry et al 1994, they typically contribute less to the sedimentary flux than other sources (Fowler et al 1991, Wassmann et al 1999, Roy et al 2000. Accordingly, many studies report low contributions from fecal pellets to the lower ocean proper (Bathmann et al 1987, Lane et al 1994, Lundsgaard & Olesen 1997 even with high secondary production in the euphotic zone (Ayukai & Hattori 1992, Viitasalo et al 1999. However, the significance of zooplankton fecal pellets extends well beyond the question of carbon sequestration.…”

Section: Introductionmentioning

confidence: 99%

Fate of organic carbon released from decomposing copepod fecal pellets in relation to bacterial production and ectoenzymatic activity

Thor

Dam²,

Rogers³

2003

Aquat. Microb. Ecol.

View full text Add to dashboard Cite

Fecal pellets were produced by Acartia tonsa fed 14 C-labeled diatom, cryptophyte, and dinoflagellate diets, and were incubated in 1.2 µm-filtered Long Island Sound seawater. Based on the 14 C label, the decrease in fpOC (fecal pellet organic carbon), the release and fate of dissolved organic carbon (DOC) and particulate organic carbon (POC), as well as bacterial production and enzymatic activity, were followed over a 96 h period. fpOC decreased by 9, 14, and 19% d -1 in diatom, cryptophyte, and dinoflagellate pellets, respectively. There was a fast, possibly passive, leakage of DOC from pellets from all 3 diets within a few hours after egestion, which may not have been utilized by attached bacteria. Bacterial production rates were 17, 12, and 31 pg C pellet -1 h -1, on diatom, cryptophyte, and dinoflagellate pellets, respectively. These were 5 orders of magnitude higher than production rates of free-living bacteria, indicating that copepod fecal pellets are hot spots of pelagic microbial production. The high production was caused primarily by high initial bacterial abundances. Accordingly, production and growth were entirely uncoupled in diatom pellets. There were no increases in abundance of attached bacteria on any of the 3 diets, indicating that the produced bacterial cells were released from the fecal pellets. Attached bacteria had a higher ectoenzymatic activity than free-living bacteria, but their production and ectoenzymatic activity were uncoupled and they only assimilated a minor fraction of the released DOC. DOC was therefore released favoring free-living microbes. The chitinase activity, which increased several-fold, was coupled to the production of attached bacteria; thus, chitin may play an important role in bacterial production on copepod fecal pellets.KEY WORDS: Copepod fecal pellets · Fecal pellet decomposition · Pelagic DOC flux · Pelagic POC flux · Attached bacterial production · Ectoenzymatic activity Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 33: [279][280][281][282][283][284][285][286][287][288] 2003 cycled (Wotton & Malmqvist 2001, Turner 2002 and that most carbon originating from these fecal pellets remains part of the long-lived organic carbon in the epipelagic (Legendre & Michaud 1998). Hence, the role of fecal pellets from small copepods is that of supplying nutrients to the epipelagic planktonic microbial community rather than maintaining the vertical flux of organic matter.Copepod fecal pellets host an extensive flora of attached bacteria (Gowing & Silver 1983, Bianchi et al. 1992, Delille & Razouls 1994, Hansen & Bech 1996. Breakdown of the fecal pellets is in part governed by microbial decomposition driven by the hydrolytic activity of these bacteria. The potential hydrolytic activity is generally high in pelagic aggregates of organic matter (Karner & Herndl 1992, Smith et al. 1992, and if this potential is fully exploited in fecal pellets, then decomposition and hence recycling of organic matter may occur rapidly....

show abstract

The origin of sedimenting detrital matter in a coastal system

Cited by 25 publications

References 9 publications

Sedimentation of copepod fecal material in the coastal northern Baltic Sea: Where did all the pellets go?

Sedimentation of copepod fecal material in the coastal northern Baltic Sea: Where did all the pellets go?

The trophic role of marine pelagic ciliates and heterotrophic dinoflagellates in arctic and temperate coastal ecosystems: A cross‐latitude comparison

Fate of organic carbon released from decomposing copepod fecal pellets in relation to bacterial production and ectoenzymatic activity

Contact Info

Product

Resources

About