Life in the Mesopelagic

The mesopelagic - or ocean twilight zone - is the dimly lit part of the ocean between the productive surface waters and the deep-sea. It is among the largest but also least explored and understood ecoystems of the planet. This vast midwater habitat is inhabited by fish, squid, jellyfish and zooplankton. Their ubiquitous presence is revealed by acoustic deep scattering layers found across all oceans.

Mesopelagic fish stocks are the largest and least exploited in the world, with a global biomass on the order of 1,000 to 10,000 million tons, maybe 10-20 times that of all other fishes combined. Many organisms in the mesopelagic rise to the surface at nighttime to feed, before migrating back to great depth before the sun returns. Therefore, mesopelagic organisms play an influential role in oceanic food webs, carbon sequestration, and biogeochemical cycling. There is also renewed interest in their commercial exploitation as feeds or food for human consumption.

Large knowledge gaps on these organisms and their role in and interactions with other parts of the marine ecosystem and global climate remain. Specifically, how much mesopelagic biomass is there and how to accurately estimate it? What controls species composition, population structure and distribution of mesopelagic communities? What is the importance of mesopelagic organisms in the diet of oceanic top predators and commercial fish stocks? What is the fraction of migrators and what controls their migration? What are the consequences of de-oxygenation and implications of harvesting of midwater organisms? We often also lack fundamental biological information e.g., physiological measurements of vital rates but also studies of life histories and behaviours are sparse.

We are currently working on the following projects:
[list projects here with one sentence description]
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Some key papers from the group