Kelps’ Long-Distance Dispersal: Role of Ecological/Oceanographic Processes and Implications to Marine Forest Conservation

Abstract

Long-distance dispersal is one of the main drivers structuring the distribution of marine biodiversity. This study reports the first occurrence of Macrocystis pyrifera and Durvillaea antarctica rafts on the southwestern warm temperate coast of the Atlantic Ocean. Our results indicate that an extreme meteo-oceanographic event, characterized by a northward, displacement of cold sub-Antarctic oceanic waters driven by an extratropical cyclone, could account for these unusual occurrences. A niche model based on known current distribution and maximum entropy principle (MAXENT), revealed the availability of suitable habitats at lower latitudes, outside their actual distribution edges. The distributional boundaries, mainly driven by temperature and irradiance, suggest the existence of environmental suitability in warm temperate areas, as well as in the Northern Hemisphere off Atlantic and Asian coasts. These theoretical edges and respective environmental drivers agree with the physiological affinities of both species, supporting the hypothesis that these variables act as limiting factors for their occurrences in tropical or warmer areas. Emerging regions can function as Diversity 2018, 10, 11; doi:10.3390/d10010011 www.mdpi.com/journal/diversity Diversity 2018, 10, 11 2 of 25 refuges and stepping-stones, providing substrate with adequate habitat conditions for recruitment of propagules, allowing eventual colonization. Long dispersal events reinforce the need for an extensive discussion on selective management of natural dispersion, biological invasions, refuge mapping and conservation initiatives in a transnational perspective.

Climate-Driven Range Shifts of Brown Seaweed Sargassum horneri in the Northwest Pacific

“…Response curves showed that mean primary productivity was positively correlated with the habitat suitability of S. horneri. This is consistent with primary productivity projected as being a major variable shaping the current distribution of seaweeds Undaria pinnatifida (Báez et al, 2010), Macrocystis and Durvillaea (Bernardes Batista et al, 2018).…”

The role of continental shelf bathymetry in shaping marine range shifts in the face of climate change

“…This break in shelf area continuity, in tandem with the Antarctic Polar Front and the Antarctic Circumpolar Current, has limited poleward range expansion of species through evolutionary time (Rogers, 2007; Wilson et al, 2016). However, evidence is accumulating for some dispersal of plant and invertebrate species across the Antarctic Polar Front through rafting and rare long distance dispersal events, which may facilitate some range shifts of a diverse array of species despite the lack of contiguous continental shelf area (Bernardes Batista et al, 2018; Fraser et al, 2017).…”

Ecological biomechanics of damage to macroalgae

“…For example, Turbinaria ornata are weaker and more buoyant when reproductive, so hydrodynamic forces break their stipes and they form floating aggregations where they release gametes and are transported to new sites by currents ( Stewart, 2006b ). Similarly, drifting in ocean currents by broken-off reproductive kelp aids long-distance dispersal ( Bernardes Batista et al, 2018 ; Fraser et al, 2020 , 2022 ).…”