A simple range expansion model of multiple pathways: the case of nonindigenous green crab Carcinus aestuarii in Japanese waters

Abstract

Forecasting the range expansion of nonindigenous organisms enables effective quarantine and the development of pre-arrival countermeasures, as well as raises public and scientific concerns among the general public. Here, we present an approach to forecasting the range expansion of the nonindigenous green crab Carcinus in Japanese waters, with consideration of the human-mediated shipping and natural dispersal. Two types of shipping, namely, primary transport to Japan via long-distance oceangoing shipping and secondary transport within Japan via short-distance coastal shipping, were considered. The presence and absence of the crab in 50-km shoreline segments were obtained at 5 year intervals from 1985 to 2005, based on observation records by professional and amateur naturalists. Two types of dispersal kernel, namely, conventional logistic regression and a multiplicative immigration model considering multiple pathways explicitly, were compared. The multiplicative immigration model gave significantly better results. Natural dispersal was the most significant factor, in spite of its low expansion rate: secondary transport by coastal shipping was the second. Transport by international ocean-going shipping was not statistically significant, suggesting quite a small immigration probability of the crab by long voyages. Stochastic simulations forecasted that the crab will invade most of the coasts of western Japan along the Pacific Ocean and Seto Inland Sea by 2055, and will become widespread all over the country by 2205. Quarantine scenarios to eliminate transport by vessels revealed that preventing crab transport by domestic coastal vessels may delay the arrival of crabs in Hokkaido and the northern Japan area by 700 years at maximum.

Interspecific Hybridization and Mitochondrial Introgression in Invasive Carcinus Shore Crabs

“…Natural selection for particular mitochondrial types in intertidal animals has typically been associated with thermal physiology related to mitochondrial respiration [44]. However, the thermal regime of Japanese waters surrounding Honshu, Shikoku, and Kyushu Islands, where Carcinus has been recorded, is far more similar to conditions observed in the Mediterranean than those in Atlantic Europe [35]. This suggests that any temperature-related selection exerted on the mitochondrial genome in this region would most likely favor C. aestuarii types over C. maenas .…”

Generating an agricultural risk map based on limited ecological information: A case study using Sicyos angulatus

“…Predicting the risk imposed by invasive species will enable the development of pre-arrival countermeasures and will help to avoid social issues, such as the need to reach consensus regarding countermeasures (Koike and Iwasaki 2011). Biological invasions can sometimes cause very severe damage, whereas practitioners usually try to solve the problem after the damage occurs.…”

“…The most cost-effective way of managing invasive species is to prevent their introduction and establishment within high-risk areas (Leung et al 2002;Koike and Iwasaki 2011). Thus, our approach provides support for establishing cost-effective management plans, as it actualizes the timely prediction of high-risk areas without the use of detailed ecological information on the target species before or during the early stages of invasion.…”

Supervised forecasting of the range expansion of novel non‐indigenous organisms: Alien pest organisms and the 2009 H1N1 flu pandemic

“…We did not use any pathway information in our prediction approach (Figure ). The pathways of unintentional introductions of alien organisms are often unclear, and quantitative data on the region‐to‐region transport of humans and cargo are frequently unavailable even when the type of pathway is qualitatively known (Ferguson et al, ; Koike & Iwasaki, ; Maynard & Nowell, ). Therefore, we expect that our proposed approach will be useful in predicting the range expansion of various alien organisms when detailed information is lacking, particularly in the early stage of a pandemic.…”

“…A metapopulation model can be used to estimate the geographical range expansion when only the occurrence or absence of the alien organism in a region needs to be considered (e.g., Colizza et al, 2007;Koike, 2006). Although metapopulation models are relatively simple, they still require quantitative pathway data, such as the traffic density between sites or the length of the paths through continuous habitats (Colizza et al, 2007;Koike & Iwasaki, 2011). However, as in the cases of the H5N1 influenza epidemic and the introduced red fire ant, these traffic pathways are sometimes complicated owing to factors such as natural waterfowl migration and poultry trading, as with H5N1 (Vandegrift, Sokolow, Daszak, & Kilpatrick, 2010), or unidentified modes of conveyance, as with the fire ant (Ascunce et al, 2011), even though world trading is one of the most important factors (Chapman, Purse, Roy, & Bullock, 2017).…”