Although the anglerfish Lophius piscatorius is now a species of major commercial importance, our understanding of its basic biology is far from complete. Here, the early life history of L. piscatorius is investigated by otolith daily increment analysis, the application of a particle tracking model and an examination of the geographical distribution of pelagic and demersal anglerfish. Otolith incremental analysis indicates that the pelagic phase is relatively long (ca. 120 days) and growth during the first year of life is rapid. A particle tracking model predicts that pelagic post larvae of known age caught west of the Outer Hebrides could originate from the shelf edge west of Ireland, the Rockall Plateau and the northern perimeter of the North Sea, whereas those caught in the northern North Sea are likely to originate from the western edge of the Norwegian Deep and the shelf edge west and north of Scotland. The model also predicts that a large proportion of the young anglerfish originating from a spawning area located west of the Outer Hebrides will enter the North Sea and that although most of the spawning products originating at Rockall will recruit to the Rockall Plateau some may be transported northwest and some to the northern perimeter of the North Sea. The distribution of the demersal stages suggests that L. piscatorius spawns in deep water, the transition from the pelagic to the demersal phase takes place in relatively shallow water and most recruits enter the North Sea from the north and west. The finding that some juveniles may settle on the seabed hundreds of kilometres from the spawning grounds has major implications for the effective management of the fishery.
A field monitoring study was carried out to follow the changes of fine root morphology, biomass and nutrient status in relation to seasonal changes in soil solution chemistry and moisture regime in a mature Scots pine stand on acid soil. Seasonal and yearly fluctuations in soil moisture and soil solution chemistry have been observed. Changes in soil moisture accounted for some of the changes in the soil solution chemistry. The results showed that when natural acidification in the soil occurs with low pH (3.5-4.2) and high aluminium concentration in the soil solution (>3-10 mg l −1 ), fine root longevity and distribution could be affected. However, fine root growth of Scots pine may not be negatively influenced by adverse soil chemical conditions if soil moisture is not a limiting factor for root growth. In contrast, dry soil conditions increase Scots pine susceptibility to soil acidification and this could significantly reduce fine root growth and increase root mortality. It is therefore important to study seasonal fluctuations of the environmental variables when investigating and modelling cause-effect relationships.
A manipulated increase in acid deposition (15 kg S ha ¡1 ), carried out for three months in a mature Scots pine (Pinus sylvestris) stand on a podzol, acidiWed the soil and raised dissolved Al at concentrations above the critical level of 5 mg l ¡1 previously determined in a controlled experiment with Scots pine seedlings. The induced soil acidiWcation reduced tree Wne root density and biomass signiWcantly in the top 15 cm of soil in the Weld. The results suggested that the reduction in Wne root growth was a response not simply to high Al in solution but to the depletion of exchangeable Ca and Mg in the organic layer, K deWciency, the increase in NH 4 :NO 3 ratio in solution and the high proton input to the soil by the acid manipulation. The results from this study could not justify the hypothesis of Al-induced root damage under Weld conditions, at least not in the short term. However, the study suggests that a short exposure to soil acidity may aVect the Wne root growth of mature Scots pine.
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