Hurdles and opportunities in implementing marine biosecurity systems in data-poor regions.

Managing marine nonindigenous species (mNIS) is challenging, because marine environments are highly connected, allowing the dispersal of species across large spatial scales, including geopolitical borders. Cross-border inconsistencies in biosecurity management can promote the spread of mNIS across geopolitical borders, and incursions often go unnoticed or unreported. Collaborative surveillance programs can enhance the early detection of mNIS, when response may still be possible, and can foster capacity building around a common threat. Regional or international databases curated for mNIS can inform local monitoring programs and can foster real-time information exchange on mNIS of concern. When combined, local species reference libraries, publicly available mNIS databases, and predictive modeling can facilitate the development of biosecurity programs in regions lacking baseline data. Biosecurity programs should be practical, feasible, cost-effective, mainly focused on prevention and early detection, and be built on the collaboration and coordination of government, nongovernment organizations, stakeholders, and local citizens for a rapid response.

Coral reefs in the northeastern Saudi Arabian Red Sea are resilient to mass coral mortality events.

We conducted an integrated survey combining visual census and baited remote underwater video survey on the coral reefs in the northeastern Red Sea and examined their health by comparing the baseline information from two decades ago. The mean coverage of the corals of all stations was 36 %, including 32 % stony corals and 4.0 % soft corals, significantly higher and lower to previous baseline. Observed high proportion of dead corals indicated the occurrence of the events of mass mortality, and the heating events were the most likely cause. Similar levels of coral coverage compared to two decades ago indicated their resilience to past events with mass coral mortality. Small proportions of macroalgae and sea urchins indicated that they might be controlled by their predators frequently observed in both visual census and underwater video survey. Regular monitoring and careful development plans are needed to safeguard these invaluable reefs.