We hypothesised that Antarctic krill acquire UV-absorbing mycosporine-like amino acids (MAAs) from dietary algae, which produce MAAs in response to ultraviolet (UV) irradiation. To test this hypothesis, we grew cultures of Phaeocystis antarctica that had been grown under either photosynthetically active radiation (PAR, 400-750 nm) plus UV irradiation (UVR, 280-400 nm), or else PAR-only. Algae g...

1. Changes in species’ abundance and distributions caused by human disturbances can have indirect effects on other species in a community. Although ecosystem approaches to management are becoming increasingly prevalent, they require a fuller understanding of how individual behaviour determines interactions within and between species. 2. Ecological interactions involving krill are of major impor...

Krill (Euphausiids) play a vital ecosystem role in many of the world's most productive marine regions, providing an important trophic linkage. We introduce a robust modeling approach to link Cassin's auklet (Ptychoramphus aleuticus) abundance and distribution to large-scale and local oceanic and atmospheric conditions and relate these patterns to similarly modeled distributions of an important ...

Nowadays, solving constrained engineering problems related to optimization approaches is an attractive research topic. The chaotic krill herd approach considered as one of most advanced techniques. An hybrid technique exploited in this paper solve the challenging problem estimating largest domain attraction for nonlinear systems. Indeed, intelligent methodology estimation stable equilibrium est...

Antarctic krill Euphausia superba (hereafter ‘krill’) occur in regions undergoing rapid environmental change, particularly loss of winter sea ice. During recent years, harvesting of krill has in creased, possibly enhancing stress on krill and Antarctic ecosystems. Here we review the overall impact of climate change on krill and Antarctic ecosystems, discuss implications for an ecosystem-based f...

Pacific white shrimp, Litopenaeus vannamei, is the major species used in aquaculture of shrimp as of food for humans. Feed used in commercial cultivation of shrimp increasingly contains plant protein as a nutritional source, which has the advantage over animal protein in terms of both cost and sustainability. However, a problem with the use of plant protein, such as soybean meal, is that it lac...

Upward-looking acoustic Doppler current profilers (ADCPs) (300 kHz) and echosounders (125 kHz) were deployed on moorings at South Georgia to measure abundance of Antarctic krill continuously over several months. Echoes from krill were identified using the theoretical difference in echo intensity at 300 and 125 kHz and scaled to krill density using target strengths appropriate for krill in the r...

Antarctic krill (Euphausia superba; hereafter krill) are an incredibly abundant pelagic crustacean which has a wide, but patchy, distribution in the Southern Ocean. Several studies have examined the potential for population genetic structuring in krill, but DNA-based analyses have focused on a limited number of markers and have covered only part of their circum-Antarctic range. We used mitochon...

Iron is an essential nutrient for phytoplankton, but low concentrations limit primary production and associated atmospheric carbon drawdown in large parts of the world's oceans [1, 2]. Lithogenic particles deriving from aeolian dust deposition, glacial runoff, or river discharges can form an important source if the attached iron becomes dissolved and therefore bioavailable [3-5]. Acidic digesti...

BACKGROUND A population of humpback whales (Megaptera novaeangliae) spends the austral summer feeding on Antarctic krill (Euphausia superba) along the Western Antarctic Peninsula (WAP). These whales acquire their annual energetic needs during an episodic feeding season in high latitude waters that must sustain long-distance migration and fasting on low-latitude breeding grounds. Antarctic krill...