Cryptic diversity in southern African kelp.

The southern coast of Africa is one of the few places in the world where water temperatures are predicted to cool in the future. This endemism-rich coastline is home to two sister species of kelps of the genus Ecklonia maxima and Ecklonia radiata, each associated with specific thermal niches, and occuring primarily on opposite sides of the southern tip of Africa. Historical distribution records indicate that E. maxima has recently shifted its distribution ~ 70 km eastward, to sites where only E. radiata was previously reported. The contact of sister species with contrasting thermal affinities and the occurrence of mixed morphologies raised the hypothesis that hybridization might be occurring in this contact zone. Here we describe the genetic structure of the genus Ecklonia along the southern coast of Africa and investigate potential hybridization and cryptic diversity using a combination of nuclear microsatellites and mitochondrial markers. We found that both species have geographically discrete genetic clusters, consistent with expected phylogeographic breaks along this coastline. In addition, depth-isolated populations were found to harbor unique genetic diversity, including a third Ecklonia lineage. Mito-nuclear discordance and high genetic divergence in the contact zones suggest multiple hybridization events between Ecklonia species. Discordance between morphological and molecular identification suggests the potential influence of abiotic factors leading to convergent phenotypes in the contact zones. Our results highlight an example of cryptic diversity and hybridization driven by contact between two closely related keystone species with contrasting thermal affinities.

Namibia's way to Marine Spatial Planning - Using existing practices or instigating its own approach?

The territorial waters and EEZ of Namibia are part of the Benguela Current Large Marine Ecosystem in the South-East Atlantic. Growing demands and conflicts emerge although the area is not as intensely used as marine areas elsewhere. Namibia has chosen Marine Spatial Planning (MSP) as an integrated approach to facilitate sustainable ocean development and improved ocean governance. The paper explores the reality of the Namibian MSP process to date by investigating two guiding research questions: (1) What makes the Namibian approach to MSP distinct? and (2) What are the opportunities and difficulties of the Namibian MSP process in that particular context? The country's approach to MSP features a series of distinct attributes, not least due to its unique environmental and socio-economic context. Namibian MSP is highly precautionary and forward-looking given the relatively low intensity of current uses, has a strong ecosystem-based perspective due to the fairly pristine environment, is driven by a social equity and distributive justice agenda, and features a strong collaborative process governance. Whilst challenges such as limited financial resources, lacking legislation and weak links to broader ocean governance exist, the MSP process, which was linked to a systematic conservation planning process from the outset, has however resulted in a clear framework for the development of the first marine plan.

Marine Spatial Planning in the Benguela Current Large Marine Ecosystem.

The Benguela Current Large Marine Ecosystem (BCLME) in the south-east Atlantic covers the territorial waters and Exclusive Economic Zones (EEZ's) of Angola and Namibia and partly of South Africa. Increasing demands, user-user and user-environment conflicts occur throughout the area. The three countries, which are parties to the Benguela Current Convention (BCC), have begun to implement Marine Spatial Planning (MSP) to support the sustainable development of the area and enhance ocean governance. This makes the region one of the first in a developing economies context and on the African continent to introduce MSP. The article (1) traces the origin of MSP in the region and describes the reasons for its development, (2) reviews the status of MSP processes to date at the regional and national level, and (3) reflects on the regional and individual country processes in terms of differences and similarities in approach and process governance, shared opportunities and difficulties. The study finds that MSP in the region is introduced because of both strong interests to use it as a means to help grow the blue/ocean economy and as a mechanism to further the implementation of the ecosystem approach. Similar steps have been taken so far and alike approaches to MSP exist across the three countries, with the BCC as regional convention facilitating knowledge sharing and assisting to improve cross-border coherence and consistency on MSP from the outset. Although challenges, such as limited finances and data gaps exist both at national and regional level, the MSP processes to-date have created an enabling environment to develop the first marine spatial plans in each country and to exchange knowledge and experiences within the region and with other regions.

Spatio-temporal variability of copepod abundance along the 20 °S monitoring transect in the Northern Benguela upwelling system from 2005 to 2011.

Long-term data sets are essential to understand climate-induced variability in marine ecosystems. This study provides the first comprehensive analysis of longer-term temporal and spatial variations in zooplankton abundance and copepod community structure in the northern Benguela upwelling system from 2005 to 2011. Samples were collected from the upper 200 m along a transect at 20 °S perpendicular to the coast of Namibia to 70 nm offshore. Based on seasonal and interannual trends in surface temperature and salinity, three distinct time periods were discernible with stronger upwelling in spring and extensive warm-water intrusions in late summer, thus, high temperature amplitudes, in the years 2005/06 and 2010/11, and less intensive upwelling followed by weaker warm-water intrusions from 2008/09 to 2009/10. Zooplankton abundance reflected these changes with higher numbers in 2005/06 and 2010/11. In contrast, zooplankton density was lower in 2008/09 and 2009/10, when temperature gradients from spring to late summer were less pronounced. Spatially, copepod abundance tended to be highest between 30 and 60 nautical miles off the coast, coinciding with the shelf break and continental slope. The dominant larger calanoid copepods were Calanoides carinatus, Metridia lucens and Nannocalanus minor. On all three scales studied, i.e. spatially from the coast to offshore waters as well as temporally, both seasonally and interannually, maximum zooplankton abundance was not coupled to the coldest temperature regime, and hence strongest upwelling intensity. Pronounced temperature amplitudes, and therefore strong gradients within a year, were apparently important and resulted in higher zooplankton abundance.