Cardiac dysfunction affects eye development and vision by reducing supply of lipids in fish

Developing organisms are especially vulnerable to environmental stressors. We aimed to understand the underlying mechanisms of phenanthrene (Phe) and crude oil induced eye malformations. We exposed Atlantic haddock (Melanogrammus aeglefinus) embryos to a known L-type calcium channel blocker, nicardipine hydrochloride (Nic), and compared to early embryonic crude oil (Oil) and late embryonic Phe toxicity. All treatments lead to severe, eye, jaw and spinal deformities at early larval stages. At 3 days post hatching, larvae from all treatments and corresponding controls were dissected. Eyes, trunk, head and yolk sac were subjected to lipid profiling, and eyes were also subjected to transcriptomic profiling. Changes in lipid profiles and the transcriptome suggested that the dysfunctional and abnormal eyes in our treatments were due to both disruption of signaling pathways and insufficient supply of essential fatty acids and other nutrients form the yolk.

A test of the provisioning hypothesis of recruitment control in Georges Bank haddock

The haddock (Melanogrammus aeglefinus) stock of the Georges Bank region of the US Northeast Continental Shelf displays a pattern of large, episodic recruitments. Among the hypothesized controlling mechanisms is the idea that recruitment events are related to provisioning of pre-spawning haddock by the fall bloom the year before. With the occurrence of a recent large recruitment event in 2013, it would be prudent to retest this hypothesis. Fall bloom magnitude was positively correlated (r=0.645, p=0.005) with haddock survivor ratio (recruits per spawning biomass) including data from the 2013 recruitment. This relationship identifies a pathway of bottom up control of a resource species, thus focusing concern over recent changes in lower trophic level productivity.