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Identifying and conserving sites with consistently high settlement is necessary for protecting recruitment of coastal fish populations. We investigated the initial settlement patterns of coastally spawned juvenile fish entering 4 temperate estuaries with narrow entrances (< 500 m wide) on the eastern coast of Australia. Habitat structure (seagrass cover, blade length and syngnathid density), landscape (patch isolation, perimeter to area ratio and distance to ocean) and hydrological factors (maximum current speed, tidal volume and modelled delivery of passive particles) were investigated as possible explanations for settlement patterns into seagrass beds. One site within Lake Macquarie and 1 site within Smiths Lake were found to have consistently high settlement of 9 coastally spawned taxa over different months and were therefore identified as settlement 'hotspots'. The magnitude of tidal volume, the modelled delivery of passive particles and patch isolation together explained 70% of variation in settlement. Sites of high settlement were characterised as (1) being near to a high-volume channel supplying an abundance of larvae and (2) being isolated from other seagrass patches to concentrate settlement. Monthly variation in settlement, while affecting species composition and total fish abundance, did not alter the relative importance of the identified hotspots, suggesting that these common factors were driving settlement across different species.

Additional key words: Plant health, Forest pathology, riparian, root and collar rot. AbstractCommon alder (Alnus glutinosa) is an important tree species, especially in riparian and wet habitats. Alder is very common across Ireland and Northern Ireland, and provides a wide range of ecosystem services. Surveys along the river Lagan in Belfast, Northern Ireland led to the detection of several diseased Alnus trees. As it is known that Alnus suffers from a Phytophthora induced decline, this research set out to identify the presence and scale of the risk to Alnus health from Phytophthora and other closely related oomycetes. Sampling and a combination of morphological and molecular testing of symptomatic plant material and river baits identified the presence of several Phytophthora species, including Phytophthora lacustris. A survey of the tree vegetation along an 8.5 km stretch of the river revealed that of the 166 Alnus trees counted, 28 were severely defoliated/diseased and 9 were dead. Inoculation studies using potted Alnus saplings demonstrate that P. lacustris was able to cause disease, and Koch's postulates for this pathogen-host combination were completed, which suggests a future risk to Alnus health from P. lacustris in Northern Ireland.