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Port-to-port in Norway. Updating your booking. Photo: Stefan Dall. Glacier in the Liefdefjord. In the spring, beautiful colours and contrasts frame dramatic glaciers, majestic mountain formations, deep fjords, buzzing bird cliffs and endless arctic tundra among the wonders of Svalbard geology. The Midnight Sun makes it possible to fill your days and nights with unforgettable experiences.
Kayaking in Magdalenefjord at sunset. Hurtigruten has unmatched experience in Svalbard — dating back as far as On this voyage we will visit the North-Western coast of Svalbard, a stunning region of pristine nature.
Arctic Spring is an ideal time to visit Spitsbergen; the light is beautiful, and nature returns to life in all its glory. Explore Svalbard with the experts on an expedition cruise designed to show you the very best of this Arctic paradise under the Midnight Sun, as we discover the realm of the mighty polar bear. Itinerary What's included Your ship Practical information.
Itinerary What's included Your ship Practical information Check prices and availability. Itinerary Hurtigruten offers unique expedition cruises to some of the most remote and pristine waters of the world. As with all expeditions; nature prevails. Safety and unparalleled guest experiences are at all times our top priorities.
All our indicative itineraries are continuously evaluated for adaptions, whether this is due to constraints the elements unexpectedly presents — or exciting possibilities nature and wildlife offer. That is why we call it an expedition. Day 1. On arrival, we transfer you to your hotel for an overnight.
Midnight Sun in Longyearbyen, Svalbard. Watch out - there are more polar bears than humans on the Svalbard archipelago! Welcome to Longyearbyen, Svalbard. The widespread nature of both pelagic groups will mean they have low endemicity and little influence on the delimitation of the biogeographic realms. Thus, when we analyzed the data using only widespread and pelagic species we found fewer biogeographic realms Fig.https://ymosipihipyh.tk
Frontiers | Global Observational Needs and Resources for Marine Biodiversity | Marine Science
Similarly, a review of pelagic biogeography suggested that there may be only five pelagic biogeographic realms Endemicity will thus be most influenced by the species-rich benthic macro-invertebrates. If the abundance of cosmopolitan species is related to environmental conditions, then ecologically-distinct regions are likely to be found, such as those found for 15 species of pelagic fishes However, these do not align with biogeographic realms based on endemicity , because they reflect habitat suitability for the species within their geographic range.
Pelagic and benthic biota tend to be independently sampled, studied, and reported upon, reinforcing impressions that they may be distinct biogeographically. However, there are more benthic species that spend part of their life-cycle in the plankton meroplankton than there are holo-plankton, so this division is artificial Many species in the plankton will return to the seabed during their life, and thus their planktonic and benthic biogeographies will overlap.
In both the pelagos and benthos the most widespread species are the microscopic biota microbial, meiofauna, and plankton 35 and mobile megafauna e. Thus, these very small and very large taxa have less species globally The Black Sea and inner Baltic Sea had a biogeographically distinct biota at a global level due to the influence of freshwater species. This illustrates how salinity determines aquatic species distributions at a global level.
However, beyond these brackish seas, salinity varies little in the ocean and thus has no further effect on biogeography. The closer similarity of the biota between the tropical west Atlantic and tropical east Pacific, than the Mediterranean and Red Sea, reflected the more recent establishment of the Central American compared to the Asia-Africa land barrier. Thus, continental drift has been a primary factor in determining marine endemicity, as it has on land 5 , 6. It may be argued that ocean biogeography should be considered in four dimensions e.
However, two dimensions may be as adequate for marine biodiversity mapping as they are for terrestrial because changes in depth and altitude coincide with changes in latitude and longitude, and pelagic and deep-sea species are relatively cosmopolitan compared to benthic and coastal. Just as land fauna and flora form distinct communities with altitude, biogeographic boundaries may also occur with depth. The oceans are often divided into bathyal, abyssal, and hadal zones in recognition that the deep-sea fauna varies with depth Although oceans are three-dimensional 3D habitats, most zooplankton show diel vertical migration such that there is no evidence of vertically separated zoogeographic regions in the open pelagic oceans Similarly, habitats on land are 3D, but all taxa directly or indirectly e.
The open-ocean realms found in the present study reflect a combination of widely dispersed pelagic species and deep-sea species. Deep-sea species tend to have wider depth ranges than coastal species, and abyssal species are largely a subset of bathyal species, although there may be exceptions 10 , Geographic ranges are generally larger for pelagic than benthic, and deep-sea than shallow water, species 10 , Thus, as we found, there are likely to be fewer biogeographic realms in pelagic and deep seas than in coastal areas, so mid-ocean biogeographic realms would be expected to be larger than coastal.
The effect of coastal species on our realms is evident where the Maldives extend into the middle of the Indian Ocean realm Other islands may influence other mid-ocean realms e.
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Most realms were coastal and continental shelf. Offshore realms were larger because they have lower endemicity and betadiversity in the pelagic and deep-sea environments. Thus, the coastal realms should be considered to extend to the m depth contour. The sediment covered seabed has low slope 42 , so the deep-sea is a large, but relatively uniform habitat compared with coastal environments. Thus the deep-sea and its associated pelagos is the largest realm on Earth. With the exception of the Rio de La Plata realm 24 , most of the additional regions proposed here 18, 19, 21, 22 are deep-sea and pelagic; Ekman lacked data for these regions.
WANDERINGS IN WESSEX
Based on a review of current knowledge, Spalding et al. In contrast, Ecoregions were based on environmental conditions and other factors, and so with two exceptions, we found no evidence for biogeographic differences between them. However, the latter two Baltic and Black Seas included freshwater species. Kulbicki et al. Within the Kulbicki realms were regions that mapped to our realms 9 Hawaiian central north Pacific , 10 south-east Pacific , and 17 mid-south Pacific.
Thus, our realms were supported by their analysis and provide some additional biogeography. Where the boundaries of Kulbicki et al. Keith et al. They distinguished eleven faunal regions which geographically aligned to six of our realms.
Our analysis thus provides empirical support for many of the marine biogeographic realms proposed based on reviews that synthesized taxon-specific and regional knowledge. It further illustrates that one global classification may be realistic and suggests close spatial relationships between the pelagic and deep-sea realms. Thus, it is also possible that there will be more realms eventually distinguished than we have found.
Abyssal and hadal endemics appear to exist 13 , but may not have been sufficiently sampled or represented in the present data to form distinct biogeographic realms. Some regional studies have proposed biogeographic regions within the realms proposed here, such as in southern Africa 45 , the Mediterranean 46 , Caribbean 30 , bathyal and hadal depths 13 , eastern North America 47 , and many other areas Our exploration of alternative similar coefficients and cell sizes Fig.
However, network theory analysis 49 , 50 suggested that our Caribbean realm may extend down the coast of Brazil and merits further analysis with additional data. Cluster analyses of the distribution of 70 species of seagrass and 77 species of razor clams distinguished 11 and 16 regions, respectively, some of which were very small 51 , The relatively low number of species in these studies may explain why they found less than the 23 coastal realms in the present study.
In some cases, such as Spalding et al. The biogeographic boundaries in these and the present study are best considered a hypothesis that should be tested as more species distribution data become available.
Introduction: “The Fiery Frontier and the Dong World”
The geographic boundaries were coincident with land barriers to species dispersal, low-salinity seas with freshwater species, and coastal and offshore environments separated by depth. Further research is required to determine what environmental factors explain other realm boundaries. Whether boundaries will change as species change their distributions in response to climate change and human mediated species introductions remains to be seen.
For example, species have colonized the Mediterranean from the Red Sea through the Suez Canal 46 and will colonize the Atlantic from the Pacific as the polar ice retreats 53 , With climate change, sea temperature will change mostly in high northern latitudes 55 , and so richness is predicted to increase there 56 , 52 , although species may also change their depth distribution 57 , While changing species distributions will change richness, community composition, and ecosystems, whether they will change the relative location of biogeographic boundaries remains unknown.
While our choice of similarity index Jaccards has been the most popular in biogeography analyses 3 , indices that are not influenced by species richness, that can distinguish between gradient and nestedness patterns of species turnover e. We found our findings robust to alternative similarity indices and spatial units, including using a version of the data from OBIS Fig. Similarly, Mouillot et al. We encourage new analyses using these and related measures in biogeography. Such studies will need to consider the limitations of using primary data vs.
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Moreover studies that are less than global in taxonomic and geographic scope need to account for possible boundary effects. For example, species apparently endemic may occur outside the study area or habitat. A coral reef fish species may also occur on rocky reefs and coastal rocky reef fish can occur amongst deep-sea cold-water coral reefs In addition, while species distribution models can predict species ranges e. Our preliminary analysis of modeled species ranges from AquaMaps 64 returned patterns mirroring the environmental variables used to generate the models rather than patterns of endemicity.