Search the SPREP Catalogue

The electronic newsletter of the Pacific Invasives Learning Network (PILN) - reporting on invasives news from PILN teams and the Pacific region.

Biological control of introduced weeds in the 22 Pacific island countries and territories (PICTs) began in 1911, with the lantana seed-feeding fly introduced into Fiji and New Caledonia from Hawaii. To date, a total of 62 agents have been deliberately introduced into the PICTs to control 21 weed species in 17 countries. A further two agents have spread naturally into the region. The general impact of the 36 biocontrol agents now established in the PICTs ranges from none to complete control of their target weed(s). Fiji has been most active in weed biocontrol, releasing 30 agents against 11 weed species. Papua New Guinea, Guam, and the Federated States of Micronesia have also been very active in weed biocontrol. For some weeds such as Lantana camara, agents have been released widely, and can now be found in 15 of the 21 PICTs in which the weed occurs. However, agents for other commonly found weeds, such as Sida acuta, have been released in only a few countries in which the weed is present. There are many safe and effective biocontrol agents already in the Pacific that could be utilised more widely, and highly effective agents that have been released elsewhere in the world that could be introduced following some additional host specificity testing. This paper discusses the current status of biological control efforts against introduced weeds in the 22 PICTs and reviews options that could be considered by countries wishing to initiate weed biological control programmes.

Biological control of weeds in Vanuatu began in 1935, with the introduction of the tinged Teleonemia scrupulosa to control Lantana camara. To date, nine biological control agents have been intentionally introduced to control eight weed species. Seven of these agents have established on their respective hosts while an eighth, Zygogramma bicolorata, an agent for Parthenium hysterophorus has only recently been released and establishment is unlikely.

Rhinella marina is a Neotropical toad that has been introduced widely worldwide. Its toxic effects to frog-eating predators threaten the native and domestic fauna of some regions where it has been introduced. Despite previous studies suggesting two genetically distinct cryptic species within R. marina, one east and one west of the Andes, its taxonomic status remained unresolved due to the absence of morphological complementary evidence. For the first time, data from two mitochondrial genes (ND3 and CR) and 23 morphometric landmarks are combined to evaluate the taxonomic status of this species. Our results support the hypothesis of two separate evolutionary lineages within R. marina and demonstrate that these lineages have significantly diverged in skull shape. We identified two distinct morphotypes, one eastern and one Andean western, with no overlapping morphospaces. The geographic pattern of genetic variation was consistent with a stable structured population with no evidence of recent demographic or geographic expansions. The concordance between the observed geographic patterns in morphometric and genic traits calls for the recognition of two species under R. marina name.

Fiji has demonstrated a strong commitment to cetacean conservation via national, regional and international plans and agreements. To provide baseline information in support of these efforts, this paper provides an updated listing of cetacean species found in Fijian waters and identifies locations where cetaceans have been noted on a consistent basis. Information for this review was sourced from peer-reviewed publications, field reports, historical whaling records, national consultations, anecdotal and opportunistic sources, as well as a national database held by the Fiji Government’s Department of Fisheries. Reliable and recent records were confirmed for 10 cetacean species in Fijian waters. In addition, less reliable records and regional species’ information provides support for the occurrence of at least 14 additional species or groups of similar-looking species that could not be identified more specifically. Thirteen hotspot areas within the Fiji Economic Exclusive Zone were preliminarily identified as being particularly important for cetaceans, including numerous sites within the Vatu-i-Ra and Lomaiviti passages and surrounding waters. Issues with the available data include uneven coverage, inherent biases within available sources, and difficulties with species identification and verification in some cases. Nevertheless, it is hoped that this review will provide a reference point from which to move forward with cetacean management and conservation efforts in Fiji.

National or Territory Invasive Species Strategies and Action Plans (NISSAP) are a critical document to ensure invasive species management is coordinated within a country or territory and that the different sectors involved with invasive species management are working together toward the same goals. NISSAP are essential to show political will for managing invasive species and are looked upon favourably by funding bodies.