Distribution, abundance, behavior and metabolism of Periphylla periphylla, a mesopelagic coronate medusa in a Norwegian fjord

Vertical migration of the mesopelagic jellyfish Periphylla periphylla (Scyphozoa: Coronatae) was studied by use of hull-mounted and submerged echosounders in a ,440 m deep Norwegian fjord. The research vessel was kept at a fixed position so that individual jellyfish remained in the acoustic beam for prolonged periods in the low advective environment of the deep fjord basin. The population of jellyfish was divided into different vertical modes with different migration behavior. A scattering layer (SL) of P. periphylla was located at 150-200 m during the day; it migrated coherently to the upper 50 m at night and returned to depth the next morning. A deeper SL seemed to remain below 250 m both day and night. However, focus on individuals revealed additional, asynchronous migration activity. A pulse of P. periphylla left upper layers already a few hours after sunset, and there was interchange of individuals between shallow and deep water throughout the night, including ascent of individuals from the apparent nonmigrating deepest SL. Vertical migration velocities were ,2 cm s 21 both during ascent and descent, irrespective of time. Different types of swimming behavior were reflected in the acoustic records, affecting the recorded backscatter.

Section: Methodsmentioning

confidence: 66%

Section: Discussionmentioning

confidence: 99%

“…Maps of the study site and Limnol. Oceanogr., 52(3), 2007, 975-983 adjacent regions are given in Fosså (1992) and Youngbluth and Bå mstedt (2001).…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Diel vertical migration of individual jellyfish (Periphylla periphylla)

Kaartvedt

Klevjer

Torgersen

et al. 2007

Jellyfish decomposition at the seafloor rapidly alters biogeochemical cycling and carbon flow through benthic food‐webs

Sweetman

Chelsky

Pitt

et al. 2016

Jellyfish blooms have increased in magnitude in several locations around the world, including in fjords. While the factors that promote jellyfish blooms and the impacts of live blooms on marine ecosystems are often investigated, the post-bloom effects from the sinking and accumulation of dead jellyfish at the seafloor remain poorly known. Here, we quantified the effect of jellyfish deposition on short-term benthic carbon cycling dynamics in benthic cores taken from a cold and deep fjord environment. Respiration was measured and 13 C-labeled algae were used as a tracer to quantify how C-flow through the benthic food web was affected over 5 d in the presence and absence of jellyfish carcasses. Benthic respiration rates increased rapidly (within 2 h) in the jellyfish-amended cores, and were significantly higher than cores that were supplied with only labeled phytodetritus between 17 h and 117 h. In the cores that were supplied with only labeled phytodetritus, macrofauna dominated algal-C uptake over the 5 d study. The addition of jellyfish caused a rapid and significant shift in C-uptake dynamics: macrofaunal C-uptake decreased while bacterial C-uptake increased relative to the cores supplied with only phytodetritus. Our results suggest that the addition of jellyfish detritus to the seafloor can rapidly alter benthic biogeochemical cycling, and substantially modify C-flow through benthic communities. If our results are representative for other areas, they suggest that jellyfish blooms may have cascading effects for benthic ecosystem functions and services when blooms senesce, such as enhanced bacterial metabolism and reduced energy transfer to upper trophic levels.

Pan‐Arctic distribution modeling reveals climate‐change‐driven poleward shifts of major gelatinous zooplankton species

Pantiukhin,

Verhaegen,

Havermans

2024

Anthropogenic activities, including climate change, are hypothesized to cause increases in gelatinous zooplankton population sizes and blooms. In the most rapidly changing ecosystem, the Arctic Ocean, this hypothesis has not yet been verified, and gelatinous zooplankton is commonly excluded from large‐scale modeling studies. Our modeling study is based on an extensive biogeographic dataset, aggregating from four open‐source databases (Ocean Biodiversity Information System, Global Biodiversity Information Facility, Jellyfish Database Initiative, and PANGAEA). It includes data on eight of the most reported gelatinous zooplankton taxa of the pan‐Arctic region (Aglantha digitale, Sminthea arctica, Periphylla periphylla, Cyanea capillata, Oikopleura vanhoeffeni, Fritillaria borealis, Mertensia ovum, and Beroe spp.). By coupling three‐dimensional species distribution models with oceanographic components from the Max Planck Institute Earth System Model (MPI‐ESM1.2), run for historical (1950–2014) and future (2050–2099) periods under the shared socioeconomic pathway SSP370 scenario forcing, we identified species with expanding or contracting habitat ranges in response to climate change. Our projections indicated a general tendency for gelatinous zooplankton distributions to shift, with varying degrees of suitable habitat expansion (largest for the scyphozoan C. capillata ~ +180%) or contraction (largest for the hydrozoan Sm. arctica ~ −15%). Seven of the eight species modeled, which—similar to the majority of gelatinous taxa occurring in the Arctic Ocean—predominantly represented arcto‐boreal and boreal taxa, are projected to shift to northern latitudes. Hence, profound impacts on the Arctic marine environment and associated ecosystem services can be expected.