Vessel traffic patterns in the Port of Kaohsiung and the management implications for preventing the introduction of non-indigenous aquatic species

Ballast Water Management Strategy to Reduce the Impact of Introductions by Utilizing an Empirical Risk Model

The introduction of non-indigenous aquatic species (NIASs) was identified as one of the major threats to aquatic ecosystems. Shipping is one of the potential invasive pathways for the introduction of marine NIASs, mainly via ballast water, sediments, and ship fouling. In addition, The International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention) aims to mitigate the introduction risk of harmful aquatic organisms and pathogens (HAOPs) via ships’ ballast water and sediment. Some of these species can be very harmful and cause loss of biodiversity, adverse environmental consequences, and economic and social impacts. In this study, an empirical model based on the environmental similarity and the vessel characteristics was used to assess the risk associated with the ballast water, for the incoming vessels to the port of Kaohsiung and port of Riga. The priority for port state control (PSC) inspection was established and recommended for better ballast water management.

Modeling and evaluation of the oil-spill emergency response capability based on linguistic variables

An evaluation of the oil-spill emergency response capability (OS-ERC) currently in place in modern marine management is required to prevent pollution and loss accidents. The objective of this paper is to develop a novel OS-ERC evaluation model, the importance of which stems from the current lack of integrated approaches for interpreting, ranking and assessing OS-ERC performance factors. In the first part of this paper, the factors influencing OS-ERC are analyzed and classified to generate a global evaluation index system. Then, a semantic tree is adopted to illustrate linguistic variables in the evaluation process, followed by the application of a combination of Fuzzy Cognitive Maps (FCM) and the Analytic Hierarchy Process (AHP) to construct and calculate the weight distribution. Finally, considering that the OS-ERC evaluation process is a complex system, a fuzzy comprehensive evaluation (FCE) is employed to calculate the OS-ERC level. The entire evaluation framework obtains the overall level of OS-ERC, and also highlights the potential major issues concerning OS-ERC, as well as expert opinions for improving the feasibility of oil-spill accident prevention and protection.

Rapid assessment of target species: Byssate bivalves in a large tropical port

Rapid assessment sampling for target species is a fast cost-effective method aimed at determining the presence, abundance and distribution of alien and native harmful aquatic organisms and pathogens that may have been introduced by shipping. In this study, the method was applied within a large tropical port expected to have a high species diversity. The port of Kaohsiung was sampled for bivalve molluscan species that attach using a byssus. Such species, due to their biological traits, are spread by ships to ports worldwide. We estimated the abundance and distribution range of one dreissenid (Mytilopsis sallei) and four mytilids (Brachidontes variabilis, Arcuatula senhousa, Mytilus galloprovincialis, Perna viridis) known to be successful invaders and identified as potential pests, or high-risk harmful native or non-native species. We conclude that a rapid assessment of their abundance and distribution within a port, and its vicinity, is efficient and can provide sufficient information for decision making by port managers where IMO port exemptions may be sought.

Assessing exemptions under the ballast water management convention: preclude the Trojan horse

The International Maritime Organization (IMO) Ballast Water Management Convention (BWMC) is a powerful instrument aimed at reducing spread of harmful aquatic organisms and pathogens (HAOPs). As BWMC is expected to enter into force soon, shipping companies will start seeking exemptions for ballast water management in accordance with BWMC Regulation A-4. However, without scientifically robust risk assessment (RA) and consistent rules, the exemptions may introduce a new form of risk within a convention generally designed to reduce risks. This paper describes an adaptive system for granting exemptions, consisting of six major components: target species selection procedure, port-to-port RA, monitoring, information support, administrative decision and review process. The system is based on key principles defined in the IMO guidelines for RA and is designed to continuously accumulate evolving experience on granting exemptions. The ultimate goal is to contribute to the control of the spread of HAOPs, without placing an unnecessary burden on the shipping industry.

Tracking invasion histories in the sea: facing complex scenarios using multilocus data

In recent years, new analytical tools have allowed researchers to extract historical information contained in molecular data, which has fundamentally transformed our understanding of processes ruling biological invasions. However, the use of these new analytical tools has been largely restricted to studies of terrestrial organisms despite the growing recognition that the sea contains ecosystems that are amongst the most heavily affected by biological invasions, and that marine invasion histories are often remarkably complex. Here, we studied the routes of invasion and colonisation histories of an invasive marine invertebrate Microcosmus squamiger (Ascidiacea) using microsatellite loci, mitochondrial DNA sequence data and 11 worldwide populations. Discriminant analysis of principal components, clustering methods and approximate Bayesian computation (ABC) methods showed that the most likely source of the introduced populations was a single admixture event that involved populations from two genetically differentiated ancestral regions - the western and eastern coasts of Australia. The ABC analyses revealed that colonisation of the introduced range of M. squamiger consisted of a series of non-independent introductions along the coastlines of Africa, North America and Europe. Furthermore, we inferred that the sequence of colonisation across continents was in line with historical taxonomic records - first the Mediterranean Sea and South Africa from an unsampled ancestral population, followed by sequential introductions in California and, more recently, the NE Atlantic Ocean. We revealed the most likely invasion history for world populations of M. squamiger, which is broadly characterized by the presence of multiple ancestral sources and non-independent introductions within the introduced range. The results presented here illustrate the complexity of marine invasion routes and identify a cause-effect relationship between human-mediated transport and the success of widespread marine non-indigenous species, which benefit from stepping-stone invasions and admixture processes involving different sources for the spread and expansion of their range.

Long-term coexistence of non-indigenous species in aquaculture facilities

Non-indigenous species (NIS) are a growing problem globally and, in the sea, aquaculture activities are critical vectors for their introduction. Aquaculture introduces NIS, intentionally or unintentionally, and can provide substratum for the establishment of other NIS. Little is known about the co-occurrence of NIS over long periods and we document the coexistence over decades of a farmed NIS (a mussel) with an accidently introduced species (an ascidian). Both are widespread and cause serious fouling problems worldwide. We found partial habitat segregation across depth and the position of rafts within the studied farm, which suggests competitive exclusion of the mussel in dark, sheltered areas and physiological exclusion of the ascidian elsewhere. Both species exhibit massive self-recruitment, with negative effects on the industry, but critically the introduction of NIS through aquaculture facilities also has strong detrimental effects on the natural environment.