Lessons on Marine Protected Area Management in Northern Boreal Regions from the United States and Norway

In comparison to tropical reef systems, relatively few marine protected areas (MPA’s) exist in temperate or subarctic systems (e.g., North Pacific and North Atlantic) where species diversity is lower, abundance of individual species is often higher, and many fish species exhibit large amounts of movement during one or more of their life stages, especially as adults. A review of MPA’s in three northern areas—the Northwest Atlantic, Northeast Atlantic, and the Northeast Pacific—indicates that MPA’s can be useful management tools towards fisheries management and habitat conservation. However, achieving fishery goals, such as sustainable use of the fisheries resources, will depend on population abundance (relative to unfished conditions) and fish behavior and movement. For example, depleted populations of stationary species such as Atlantic sea scallops, Placopecten magellanicus, in the Northeast Atlantic and European lobster, Homarus grammarus, in the North Sea have responded positively to small MPA’s, whereas migratory offshore Atlantic cod, Gadus morhua, and Pacific cod, Gadus macrocephalus, apparently do not appear to benefit from closed areas because of movement into fished areas. Efficient habitat conservation requires detailed habitat mapping on relevant spatial scales. In northern boreal systems with large remote areas, this information is difficult and expensive to access. An alternative strategy of closing and protecting unexploited areas has worked well for the Aleutian Island coral closure area in Alaska. MPA’s can be effective fisheries management tools when the species to be protected have been depleted and show a small to moderate level of movement, and reproductive success is ensured. MPA’s can be effective at preserving habitat when the design is based on scientific information and takes into account the impact on the user groups.publishedVersio

Manipulation of male quality in wild tits: effects on paternity loss

Extrapair paternity (EPP) has proved to be widespread and highly variable among birds and other taxa, including socially monogamous species. A multitude of hypotheses have been put forward to explain this variation, but its occurrence is not fully understood. Male age, social dominance rank, song and breeding density or synchrony have been among the suggested correlates of EPP, but results so far are inconclusive. We interspecifically cross-fostered blue tits (Parus caeruleus) and great tits (Parus major) in the wild, thus manipulating males to exhibit reduced social dominance rank, sing aberrant songs, and consequently be perceived as low-quality males as compared to controls. This allowed us to test if male quality had an influence on loss of paternity. We found no statistically significant differences between cross-fostered and control males of either species, neither with respect to levels of cuckoldry nor proportions of extrapair young (EPY) in the broods. Paternity levels were comparable to other studies on the same species. No effect of density could be detected on levels of EPP either, while an age effect seemed to be present at least in the blue tit, EPY being almost absent in broods of older blue tit males. We conclude that the effects of male quality on paternity loss are minor, if any, in these populations. Copyright 2005.cross-fostering; early learning; extrapair paternity; microsatellite; sexual imprinting; social rearing conditions

Data from: Sperm performance in conspecific and heterospecific female fluid

Divergent sexual selection within allopatric populations may result in divergent sexual phenotypes, which can act as reproductive barriers between populations upon secondary contact. This hypothesis has been most tested on traits involved in precopulatory sexual selection, with less work focusing on traits that act after copulation and before fertilization (i.e., postcopulatory prezygotic traits), particularly in internally fertilizing vertebrates. However, postcopulatory sexual selection within species can also drive trait divergence, resulting in reduced performance of heterospecific sperm within the female reproductive tract. Such incompatibilities, arising as a by-product of divergent postcopulatory sexual selection in allopatry, can represent reproductive barriers, analogous to species-assortative mating preferences. Here, we tested for postcopulatory prezygotic reproductive barriers between three pairs of taxa with diverged sperm phenotypes and moderate-to-high opportunity for postcopulatory sexual selection (barn swallows Hirundo rustica versus sand martins Riparia riparia, two subspecies of bluethroats, Luscinia svecica svecica versus L. s. namnetum, and great tits Parus major versus blue tits Cyanistes caeruleus). We tested sperm swimming performance in fluid from the outer reproductive tract of females, because the greatest reduction in sperm number in birds occurs as sperm swim across the vagina. Contrary to our expectations, sperm swam equally well in fluid from conspecific and heterospecific females, suggesting that postcopulatory prezygotic barriers do not act between these taxon pairs, at this stage between copulation and fertilization. We therefore suggest that divergence in sperm phenotypes in allopatry is insufficient to cause widespread postcopulatory prezygotic barriers in the form of impaired sperm swimming performance in passerine birds

All data associated with Cramer et al. Ecology and Evolution

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Reproductive strategy and singing activity : blue tit and great tit compared

The costs and benefits of bird song are likely to vary among species, and different singing patterns may reflect differences in reproductive strategies. We compared temporal patterns of singing activity in two songbird species, the blue tit (Cyanistes caeruleus) and the great tit (Parus major). The two species live side by side year round, and they have similar breeding ecology and similar rates of extra-pair paternity. However, they differ in two aspects of reproductive strategy that may have an influence on song output: blue tits are facultatively polygynous and have a fairly short breeding season with almost no second broods, whereas great tits are socially monogamous but more commonly raise second broods. We found that great tit males continued singing at high levels during the egg-laying and incubation periods, while monogamously paired blue tit males strongly reduced singing activity after the first days of egg-laying by their female. Since males of both species sang much more intensely shortly before sunrise than after sunrise, at midday or in the evening, this difference was most conspicuous at dawn. No differences in singing activity were found within species when testing for male age. We suggest that in contrast to blue tits, great tit males continued singing after egg-laying to defend the territory and to encourage the female for a possible second brood

Toward Improved Estimation of the Dynamic Topography and Ocean Circulation in the High Latitude and Arctic Ocean: The Importance of GOCE

The Norwegian Sea circulation plays a key role in maintaining the mild climate of the northwestern Europe via the transport of warm Atlantic Water pole-ward. The first paper addresses the advective currents connecting the two branches of the Norwegian Atlantic Current and shows the general spin up of the Norwegian Sea circulation during winter with the exception of the flow over the Mohn Ridge. The variability in the surface velocities in the Norwegian Sea is found to be deep reaching, which supports the use of altimetry to monitor the variability of the poleward transport of Atlantic Water. A strengthening and weakening of the Atlantic inflow east of the Faroe Islands has a consistent response along the entire slope current. However, a stronger western inflow, observed north of the Faroe Islands, is associated with more flow of Atlantic Water into the slope current. This finding suggest that a substantial fraction of Atlantic Water that eventually enters the Barents Sea or the Arctic through the Fram Strait, may originate from the western inflowing branch of Atlantic Water to the Nordic Seas, and that the two branches of northward flowing Atlantic Water cannot be considered as separate flows. Paper 2 examines the influence of the surface circulation, eddy activity and local heat loss on the spatial distribution and temporal evolution of dense water formation in the Lofoten Basin. Evidence of intrusion of Atlantic Water into the central Lofoten Basin due to buoyant waters in the eastern part of the basin is found. With the support of hydrographic and satellite datasets, the concept of separate western and eastern regions of the Lofoten Basin is introduced and a link between the western Lofoten Basin and Faroe Shetland overflow waters is identified. Paper 3 addresses an anomalous anticyclonic vortex in the Nordic Seas, which is situated in the western Lofoten Basin. The vortex’ surface and vertical characteristics on seasonal, inter-annual, and climatological time-scales are quantified, relevant forcing mechanisms are addressed, and its uniqueness in the Nordic Seas is documented. In the final paper, a new mean dynamic topography (MDT) is estimated for the North Atlantic and the Arctic from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite gravity anomaly data. The new GOCE-based MDT is assessed and compared to independent steric height observations, other state-of-the-art MDTs and three coupled sea-ice-ocean models, showing its usefulness in studies of high latitude ocean circulation