The Decade of Ocean Science for Sustainable Development 2021-2030 is a UN initiative that promotes a common framework for supporting stakeholders in studying and assessing the health of the world's oceans. The initiative also presents a vital opportunity to improve the integration of archaeology within the marine sciences. With the First Global Planning Meeting of the Decade held in Copenhagen at the National Museum of Denmark in May 2019, steps are already being taken to make the best of this opportunity, and the resulting creation of an Ocean Decade Heritage Network is proposed as a way forward to continue to raise awareness in the cultural heritage community about the Decade and to facilitate information sharing regarding this endeavour.

BackgroundSeveral different classifications to characterize estuarine systems have been proposed. In this present paper, one of the most important estuaries in North Africa, the Oued Loukkos (Morocco), forms a case-study for proposing a systematic classification of this particular tidal estuary according to the vertical salinity gradient.FindingsThis study, conducted using a CTD, shows that the spatial-temporal distribution of salinity depends on the stage of the tide and the upstream distance from the mouth of the river. In this case, it is also evident that the morphology of the bottom was capable of impacting the distribution of salinity by locally changing the water circulation.ConclusionsBased on the vertical salinity gradient measurement, the Oued Loukkos represents an estuarine environment with one section near its mouth that can be characterized as a mixed mesotidal estuary and another section upstream which can be characterized as a stratified mesotidal estuary. Between, there is an intermediate zone with a low vertical gradient of salinity, classified as a partially mixed mesotidal estuary. When the effect of terrestrial inputs is low compared to marine inputs, the river bed topography plays a role in the stratification of salinity by either disrupting the vertical stratification of the water or by changing the lateral distribution of salinity. The proposed classification deepens our hydrological knowledge and provides descriptive labels to the Oued Loukkos estuary. It provides a valid starting point for predicting the environmental impact of future recreational, agricultural and commercial activities on the estuary.

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Siraf is well-known archaeologically and historically as an ancient port in the Persian Gulf that prospered during the medieval period. Siraf played a leading role in facilitating maritime and terrestrial trade, connecting long-distance Indian Ocean and China routes with those in the Gulf region. Despite its history, no previous research has been dedicated to the maritime infrastructure of Siraf. Through the '2012 Siraf pilot project' a preliminary survey of the underwater and shoreline remains of this ancient port city was conducted. The site's location is unique in many respects to trade routes and logistical considerations; however, its maritime infrastructure is difficult to assess in light of the extensive threats to the site.