This palaeolimnological study investigates recent changes in the biological structure of an English shallow lake (Upton Great Broad, Norfolk). By focusing on the historical occurrence of submerged macrophytes, particularly the rare UK species, Najas marina L. (Holly-leaved Naiad), we address a management question that frequently arises for shallow lakes, namely whether to undertake sediment removal to increase water depth and/or restore conservation value. Macro-remains of aquatic macrophytes and molluscs were analysed in two littoral sediment cores and combined with other historical ecological data covering the last 100 years. Before around 1900, the lake had Chara meadows (including at least three species) and an associated species-rich community of Mollusca. Between around 1900-1970 a period of high angiosperm diversity is suggested with a reduction of Characeae and the development of patches of water-lily (particularly Nymphaea alba L.) and fen swamp in the open water. Then, after around 1970, our data indicate a rapid shift towards Najas-dominance coupled with a decrease in the seasonal length of the plant-covered period. The expansion of Najas was clearly associated with, and may even be dependent upon, a highly unusual fluid, green sediment formation that developed at the site from around the same time. Thus, despite the loss of an earlier more diverse vegetation and associated fauna, we suggest that best practice conservation may be allow natural site development and not to undertake active management such as sediment removal which might threaten the status of Najas. Our conclusion could only have been arrived at through the long-term ecological perspective that a palaeolimnological approach provides.

Many seabirds travel widely to exploit variably distributed prey resources, utilizing even profitable patches only briefly as prey become available. Assessing the relative importance of areas occupied by wind farms relies on sufficient survey effort to increase the probability of detection and later assessment to an acceptable level. Conventional techniques suffer from high sampling costs and infrequent sampling of patches within larger areas. Remote techniques, which continuously sample habitat, may offer a solution although sufficient coverage may be difficult to achieve. In this paper, we outline experiences of the use of radio telemetry on LittleTerns Sterna albifrons at their most important UK breeding site, the Great Yarmouth North Denes Special Protection Area (SPA), in relation to a 30 turbine offshore wind farm on Scroby Sands, which encroaches to 2 km from the North Denes colony. Little Terns had not been radio‐tagged previously in the UK, and the technical difficulties of tagging and subsequently following a small (55 g) diving seabird limited data collection. However, comparative data from 2 years (2003 and 2004), in which the abundance of the terns’ preferred prey varied greatly, revealed striking differences in activity and foraging patterns, which changed the perception of the scope of the birds. With an active nest, birds occupied a range of < 6.3 km2 with a range span of up to 4.6 km. In comparison, failed birds ranged widely, occupying ranges up to 52 km2 and travelling up to 27 km in a single foraging bout. As birds were recorded from 2 to 3 km offshore, the wind farm is within range of birds from the breeding colony at North Denes, although only a small proportion of foraging time was spent at such distance in the years of study. The potential value of radio (and satellite) telemetry in illustrating habitat use, perhaps to set precautionary distance limits for wind farms as well as defining actual use of particular areas including for collision risk assessment is discussed.

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Defining the at-sea foraging movements of seabirds is fundamental to understanding their ecology and can also be important in assessing the potential impact of marine developments such as offshore wind farms (OWFs). Surveys of predefined areas using aerial or boat-based transect surveys may not allow adequate assessment of the relative importance of different areas to birds. Individual-based satellite or radio-telemetry can be effective in identifying foraging ranges and preferred areas, but may not be suitable for some species. We developed a method to determine the foraging movements of breeding terns (Sterna spp.) by visually tracking individuals using a rigid-hulled inflatable boat (RHIB). Sandwich Terns (S. sandvicensis), Common Terns (S. hirundo), and Arctic Terns (S. paradisaea) were tracked from colonies in Norfolk and Anglesey, United Kingdom, from 2006 to 2008. The proportion of complete (from and to colony) trips varied from 29-60% among species, years, and colonies. Individual Sandwich Terns were tracked for periods up to 126 min over distances up to 72 km and as far as 54 km from the breeding colony, further than Arctic (up to 57 km and 29 km from the colony) and Common (to 29 km and <9 km from the colony) terns. Mean values were much smaller. Multivariate modeling of Sandwich Tern foraging trips indicated that flight speeds >50 km/hr coupled with greater distances from shore (>25 km) significantly reduced the likelihood of tracking a bird for an entire foraging trip. Use of different boats that differ in speed and performance may alleviate such issues. Visual tracking allowed us to collect data on foraging behavior, flight height, and prey capture rates, and also permitted comparisons between species. Our results indicate that visual tracking may be an effective means of determining the foraging movements and at-sea behavior of a variety of short-ranging, day-active seabirds.

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