A numerical modelling study of the interannual variability in the Indian Ocean

A simple reductA1 gravity wind-driven ocean circulation model is used to study the interannual variability in the upper layer of the Indian Ocean (24°S-23°N and 3S°E-IIS0E). The monthly mean wind stress for the period 1977-1986 are used as a forcing in the model. The model reproduces most of the observed features of the annual cycle of the upper layer circulation in the Indian Ocean when was forced with the ten-year average monthly mean wind. The circulation features and the model upper layer thickness show considerable interannual variability in most part of the basin; in particular, the Somali Current, the basin wide southern hemisphere gyre, the Equatorial Currents and the gyres in the Bay of Bengal. Six consecutive years starting from 1978 to 1983 which include two bad monsoon years of 1979 and 1982 are chosen to study the interannual variability. February circulation field shows stronger Equatorial Counter Currents in bad monsoon years, whereas. the cunents north of Madagascar flowing up to the African coast are found to be stronger in good monsoon years. The southward return flow from the Southern Gyre in August is strong and more to southern latitudes in the bad monsoon years. The flow circulated eastward to form another eddy east of Southern Gyre. The basin wide gyre of the southern hemisphere (SH) shows less variability in two consecutive normal years than in contrasting years.

Ceramics in Indian Ocean Trade

Ceramics have been extensively imported on the East African Coast over many centuries. The principal sources have been Iran and China, the latter trans-shipped through the port of Malacca and the Indian ports of the western Indian Ocean. These ceramics were used to embellish the gates and mihrabs of mosques, and the exteriors of elaborate tombs. They were vessels in homes and decorations on buildings. In the last two centuries, the old ceramics came to be supplanted by imported ware more utilitarian in make and appearance. These came in mainly from Holland, England and Germany. These products of Western Europe were influenced by the Islamic markets they had entered, while in turn these plates became an important part of the East African Coast’s architecture and Swahili traditions and homes.

Mini review: Characteristics of upwelling in several coastal areas in the world

This paper provides an overview of the upwelling processes and the controlling factors as an effort to reveal the characteristics and the intensities of upwelling events in several parts of the world. This review aimed at identifying the characteristics of upwelling and how the global climate controlling this physic phenomenon such as ENSO, IOD and Kelvin Wave. Several places in the Southeast Asia experienced high intensities of upwelling when El Nino events such as in South of Java, East Coast of Malaysia Peninsula and in Vietnam Coastal area. The results of this review found that area with the most intensive and productive upwelling in the world is South American waters and Banguela Upwelling System (BUS) in the African Coast. However, several other areas also show intensive and high productivity of upwelling, such as off the southern coast of Java Island in Indonesia and the Banda Sea and its surroundings. It is found that upwelling with stronger intensity can result in increase of mortality of certain organisms such as scallops. Additionally, increase of nutrients in a waters is often accompanied by an increase in several species of toxic algae that are harmful to the local fishery system (harmful algae blooms, HABs).

THE CONTRIBUTION OF THE DEFENCE ACT TO THE FIGHT AGAINST PIRACY

The recent events off the Horn of Africa have drawn attention again to the problem of piracy. Less publicized is an increase in pirate activities in West Africa. Despite centuries of repression, this criminal behaviour continues to present a serious challenge to the safety of shipping on which international trade depends. And the phenomenon is spreading worryingly close to a South African coast which witnessed it in the past. Indeed, pirates operated off the coast of Southern Africa as early as 1508, with pirate activity peaking at the end of the 17th century. Piracy may be generally defined as “unlawful depredation at sea involving the use or threat of violence possibly, but not necessarily, involving robbery”. The purpose of this paper is to examine the contribution of the Defence Act 42 of 2002 (hereinafter “the Act”) to the fight against piracy. South Africa has a duty to co-operate to the fullest possible extent in the repression of piracy on the high seas in terms of the 1982 UN Convention on the Law of the Sea (hereinafter “LOSC”) (art 100. South Africa ratified LOSC in 1997 after it had come into effect in 1994). In order to do so, South Africa is expected to exercise its legislative, executive and judicial jurisdictions.

Investment and Decapitalization in the Fishing Industry: The Case of the Spanish Crustacean Freezer Trawler Fleet

The objective of this work is to estimate the capital stock invested in the Spanish freezer trawler fleet dedicated to the capture of crustaceans on the African coast, for the period from 1964 to 2019. The importance of having methods for the correct measurement of the capital invested in a fishing fleet is to be able to express in monetary terms the excess catch capacity, which is a signal of overexploitation of a fishery, that is, the fleet operates at a level of effort or capacity higher than the minimum amount required to capture the desired quantity at the lowest possible cost. Following a methodology based on the permanent inventory method, we obtained a model that explains the construction value of a fishing vessel as a function of its technical characteristics. The market value in successive sales was estimated as a function of the construction value, the age of vessel and other variables. In this way, we estimated the value that the market assigns to the possible increases in individual fishing capacity and the decrease in value derived from the technical obsolescence of the vessels. Finally, we calculated the gross and net investment series and net capital stock.

The late Quaternary stratigraphy of coastal dunes and associated deposits in southern Africa

Coastal sand dune sediments with associated intraformational aeolianite, palaeosols and beachrock are found throughout much of the southern African coast, and have important roles as both Quaternary environmental archives and in recording the interplay of sediment supply, coastal processes and sea-level change. This paper examines the stratigraphy and palaeoenvironmental significance of coastal sand dunes and associated sediments, using examples mainly from South Africa but also with reference to the sandy coasts of Namibia and southern Mozambique. Based on morphological, sedimentary and dating evidence reported in the diverse literature, the stratigraphic relationship of coastal sand dune sediments to Marine Isotope Stages (MIS) is summarized, and a chronostratigraphic diagram for the period MIS 6 to 1 along the South African coast is used to identify spatially coherent sedimentary units that correspond to different regional climatic and sea-level phases. This framework provides a stratigraphic context to better examine the relationship between coastal sand dunes and external forcing during the late Quaternary in southern Africa, and to guide future field studies.

Hydroids (Cnidaria, Hydrozoa) from the Vema and Valdivia seamounts (SE Atlantic)

In this report, we analyse the benthic hydroids collected on the Vema and Valdivia seamounts during a survey conducted in 2015 in the SEAFO Convention Area, focused on mapping and analysing the occurrence and abundance of benthopelagic fish and vulnerable marine ecosystem (VMEs) indicators on selected Southeast Atlantic seamounts. A total of 27 hydroid species were identified, of which 22 belong to Leptothecata and only five to Anthoathecata. Monostaechoides gen. nov. was erected within the family Halopterididae to accommodate Plumularia providentiae Jarvis, 1922, and a new species, Monotheca bergstadi sp. nov., is also described. Campanularia africana is recorded for the first time from the Atlantic Ocean, and the Northeast Atlantic species Amphinema biscayana, Stegopoma giganteum and Clytia gigantea are also recorded from the South Atlantic. Three species were identified to the genus level only, due to the absence of their gonosomes. None of the reported species are endemic, and the hydroid community is clearly dominated by species with a wide geographical distribution in the three major oceans. Only Monotheca bergstadi sp. nov. presently has its distribution restricted to the Vema Seamount and the South African coast.

Bilingualism and language attitude in Melilla (Spain)

This study examines levels of bilingualism and language attitude in the autonomous Spanish city of Melilla. Located on the North African coast, Melilla has a population of 86,000 inhabitants that is roughly divided between residents of Iberian origin and residents of North African Origin. Based on responses to a language questionnaire (111 participants) and sociolinguistic interviews (20 participants), our results show high levels of bilingualism between Spanish and Tamazight among the sector of the population that is of North African origin, while the population of Iberian origin remains monolingual in Spanish. We also show that Spanish is the dominant language in the public domain, including administration and education, while Tamazight is maintained as a family and community language. Overall, the participants in our study express positive attitude towards the Melillan variety of Spanish and Tamazight, and their co-existence as part of the multicultural nature of the city.