Table 5.
Additional hypotheses offered but not discussed by the Higher Trophic Level Process Studies Breakout Session (3)
- The southeast Bering Sea is at carrying capacity and anthropogenic changes are causing changes in species composition.
- There is no link between pollock and herring.
- Mesopelagic myctophids compete with juvenile pollock and thereby limit offshore recruitment of pollock; therefore onshore advection of the early life history stages is critical for successful recruits.
- Fishing activities influence survival and distribution of forage fishes.
- Winter conditions are critical to survival of forage and adult fishes.
- The Bering Sea fisheries are a nutrient sink.
- The Bering Sea fisheries ³change² is due to an overall increase in primary production and not to differential partitioning between pelagic and demersal habitats.
- Jellyfish benefit juvenile pollock by providing shelter from predation.
- Older age classes of pollock have more resilience to environmental changes.
- Fish removal affects biomass, structure, and age composition.
- Fishing mortality increases variability in fish populations beyond natural variability and makes populations more vulnerable to climate change.
- Fishing removes consumers of small fish, thereby increasing availability to other predators.
- Marine mammals and birds are dependent on mesopelagic fish, particularly when pollock are absent.
- Physical environmental characteristics control distribution of forage fish.
- Cannibalism controls the structure of the fish population.
- The 50 m front is an important production area in which juvenile fish aggregate on concentrated prey, and to which higher trophic-level predators are attracted.
- The decimation of whales has left open a niche for pollock.
- Fish population structure and abundance are subject to long-term environmental changes in variables such as ocean temperature.
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