The distribution ranges of organisms, and marine animals in particular, are a manifestation of their environmental requirements, although they are often modified by the dynamics of prey and predators. Distribution range maps can also be used to infer where an activity occurs which requires the presence of a set of species, e.g., a fishery which targets them. The distribution of marine fishes and invertebrates serves as the basis for the mapping of fisheries by the Sea Around Us Project. Thus, accurate range maps are extremely important, and an earlier contribution by Close et al. (2006; FCRR 14(4): 27-37) reviews the step-by-step approach, and the assumptions used to predict the distribution of relative abundance of marine fishes and invertebrates from broad geographical limits, e.g., ocean basins, latitudinal limits, depth limits, etc., to relatively narrow polygons surrounding a number of 1⁄2 degree lat.-long. cells. Once established, such distributions, at least those referring to demersal fishes and invertebrates, can be interfaced with a map of sea bottom temperature, and inferred temperature preference profiles (TPP). These can be used, among other things, to verify the distribution ranges as predicted distributions should generate unimodal TPP, with the bulk of the distributions spanning a narrow range of temperature (~100 Celsius). As a relatively large fraction of the TPP that we obtained at first appeared bimodal, or exhibited a strong kurtosis, the assumption was revisited that the distribution of a species with regard to latitude can be simulated by an equal-sided triangle. It is shown here, for the cod (Gadus morhua), and generally for all our over 900 demersal species, that assuming a skewed triangular distribution, whose degree of skew is proportional to the temperature gradient from low to high latitude, generates more realistic distributions when compared to observed species distribution maps, although the narrowing of the uni-modal temperature probability distributions is relatively small. This correction will be implemented in all distribution ranges of demersal fishes and invertebrates in the Sea Around Us database, and used for catch allocation, and inferences on climate shifted distributions due to climate change. 3 Cited as: Pauly, D., Cheung, W.W.L., Close, C., Hodgson, S., Lam, V.W.Y. and Watson, R., 2008. Asymmetry in latitudinal, longitudinal and bathymetric distribution of marine fishes and invertebrates, p. 63-72. In: Cheung, W.W.L, Lam, V.W.Y., Pauly, D. (eds.) Modelling Present and Climate-shifted Distribution of Marine Fishes and Invertebrates. Fisheries Centre Research Report 16(3). Fisheries Centre, University of British Columbia [ISSN 1198-6727].

Global climate change is recognized as an important determining factor for the future distributions of marine organisms, notably fishes and invertebrates. Shifting of distribution range may affect global marine fisheries and have large socio-economic implications. However, globalscale evaluation of the impact of climate change on marine species is lacking. In this paper, we develop a dynamic bioclimate envelope model to predict the effect of climate change on the distributions of marine species with emphasis on commercially exploited fishes and invertebrates. First, the model infers, for various species, bioclimate envelopes based on their current distribution. Bioclimate envelopes are defined by sea water temperature, bathymetry, habitats and distance from sea ice. Secondly, the model predicts the shifting of the bioclimate envelopes induced by changes in climate variables. Simultaneously, following the shifting of the bioclimate envelopes, the model simulates movement of relative abundance through changes in population growth, mortality, larval dispersal and adult movement. We test the model with several commercially exploited fish species with widely different biogeography. The model provides reasonable and robust predictions of future distribution ranges of the four species under different scenarios of sea water warming. Moreover, the predictions are robust to major model assumptions and parameter uncertainty. Using realistic climate change predictions from the NOAA/GFDL Coupled Model, this model will be used to evaluate impacts of climate change on global marine fisheries. INTRODUCTION There is ample evidence from empirical observations and climate models indicating that mean global temperatures have been increasing over the last 100 years (IPCC 2007). Global temperature has increased by over 0.6 oC since 1900 and it may continue to increase at a rate of around 0.2 oC per decade (IPCC 2007). Biological responses to this change have been observed in both terrestrial and marine biomes (Murawski 1993; Hughes 2000; McCarty 2001; Parmesan & Yohe 2003; Perry et al. 2005; Hobday et al. 2006). The responses include changes in physiology (e.g. productivity), geographic range and phenology at population, species, community and ecosystem levels (Hughes 2000; McCarty 2001). For instance, nearly two-thirds of marine fishes in the North Sea shifted in mean latitude or depth or both over 25 years as sea temperature increased (Perry et al. 2005). During the last century, annual growth rates for the juveniles of eight long-lived fish species in the southwest Pacific increased in shallow waters and decreased in deep waters where ocean warming and cooling occurred, respectively (Thresher et al 2007). This agrees with the quantitative model of fish physiology, which predicts increasing growth performance and fecundity in higher latitude and the converse in lower latitude as sea 1 Cited as: Cheung, W.W.L., Lam, V.W.Y., Pauly, D. 2008. Dynamic bioclimate envelope model to predict climate-induced changes in distribution of marine fishes and invertebrates, p. 5-50. In: Cheung, W.W.L, Lam, V.W.Y., Pauly, D. (eds.) Modelling Present and Climate-shifted Distribution of Marine Fishes and Invertebrates. Fisheries Centre Research Report 16(3). Fisheries Centre, University of British Columbia [ISSN 1198-6727].

Global changes are shaping the ecology and biogeography of marine species and their fisheries. Macroecology theory, which deals with large scale relationships between ecology and bio- geography, can be used to develop models to predict the effects of global changes on marine species that in turn affect their fisheries. First, based on theories linking trophic energetics and allometric scaling of metabolism, we developed a theoretical model that relates maximum catch potential from a species to its trophic level, geographic range, and mean primary production within the species' exploited range. Then, using this theoretical model and data from 1000 species of exploited marine fishes and invertebrates, we analyzed the empirical relationship between species' approximated maximum catch potential, their ecology, and biogeography variables. Additional variables are inclu- ded in the empirical model to correct for biases resulting from the uncertainty inherent in the origi- nal catch data. The empirical model has high explanatory power and agrees with theoretical expec- tations. In the future, this empirical model can be combined with a bioclimate envelope model to predict the socio-economic impacts of climate change on global marine fisheries. Such potential application is illustrated here with an example pertaining to the small yellow croaker Larimichthys polyactis (Sciaenidae) from the East China Sea.

Introduction Fisheries have traditionally been seen as local affairs, largely defined by the range of the vessel exploiting a given resource. The need for countries to manage all fisheries within their Exclusive Economic Zones (EEZ), a consequence of the United Nations Convention on the Law of the Sea (UNCLOS), led to attempts to derive indicators for marine fisheries and ecosystems at the national level (see e.g., Prescott-Allen 2001). Also, it was realized that, given the large scale migration of some exploited stocks, and of distant-water fleets, an even better integration of fisheries could be achieved at the level of Large Marine Ecosystems (LMEs, Sherman et al. 2003).

Distribution ranges of commercial fish and invertebrates are required by the Sea Around Us Project for mapping of global fisheries catches. However, published ranges exist for only a small fraction of the 1231 taxa, composed of 923 species, 161 genera and 147 higher groups used in the latest version of the mapping process (Version 3.1, representative of catches from 1950 to 2003). This paper summarizes the methods employed by the Sea Around Us Project to reduce potentially global distributions to realistic ranges by identifying key ecological information for each of the 1231 commercial taxa, specifically: (i) presence in FAO area(s); (ii) latitudinal range; (iii) range-limiting polygons; (iv) depth range; and (v) habitat preferences. Furthermore, this paper presents an additional filter that outlines how (ii) and (iv) are used to correct the depth range for the effect of ‘equatorial submergence.’ Several examples are used to illustrate this process, notably the Florida pompano (Trachinotus carolinus) and the Silver hake (Merluccius bilinearis). Throughout this paper, the data sources emphasized include FishBase, other fish and invertebrate databases, and online information where applicable. In addition, simple heuristics are used to replace ecological information that is unavailable or missing. It should be noted that the Sea Around Us Project does not explicitly use temperature and primary production for any of the procedures discussed in this paper. The purpose of this is to allow for subsequent analyses of distribution ranges using these variables. INTRODUCTION The Sea Around Us Project, hosted at the Fisheries Centre, University of British Columbia, is a research initiative devoted to documenting the effects of fisheries on marine ecosystems worldwide and to propose methods to mitigate these impacts. One of the key elements of this work is mapping of marine fisheries catches onto the ecosystems from which they were extracted. The approach used therein is documented in Watson et al. (2004) and its results, regularly updated, are available on the project website (www.seaaroundus.org). This mapping approach depends crucially on the availability of distribution ranges for all taxa (species, genera, etc) reported in marine fisheries catch statistics. Previous mapping of catches relied on distributions constructed from a mixed set of ecological information that resulted in varying degrees of accuracy. This paper, therefore, documents a major revision of all commercial distribution ranges (totaling 1231 for the time period 1950 – 2003) using a set of rigorously applied filters that markedly improved the accuracy and appearance of the Sea Around Us Project maps and other products. These filters include: (i) presence in FAO area(s); (ii) latitudinal range; (iii) range-limiting polygons; (iv) depth range; (v) habitat preferences; and (vi) accounting for the effect of ‘equatorial submergence’ (Ekman, 1967) Two sample taxa are used to illustrate the results of the filter process, the Florida pompano (Trachinotus carolinus) and the Silver hake (Merluccius bilinearis), each representing pelagic and demersal species, respectively. Other species are used to illustrate specific aspects of this filter process, and are referred to in the appropriate section. 1 Cite as: Close, C., Cheung, W., Hodgson, S., Lam, V., Watson, R., Pauly, D., 2006. Distribution ranges of commercial fishes and invertebrates. In: Palomares, M.L.D., Stergiou, K.I., Pauly, D. (eds.), Fishes in Databases and Ecosystems. Fisheries Centre Research Reports 14(4), pp. 27-37. Fisheries Centre, University of British Columbia [ISSN 1198-6727]. Distribution of commercial fishes and invertebrates, Close, C. et al. 28 The procedures presented here avoid use of temperature and primary production to define or refine distribution ranges for any of the taxa. This was done in order to allow for subsequent analyses of distribution ranges to be legitimately performed using these variables. This differs from previous construction methods of distribution maps that used primary production to distinguish area of low vs. high abundance within a taxon’s distribution range (Watson et al., 2004). MATERIAL AND METHODS The ‘filters’ used here are listed in the order that they are applied; each filter is documented with a figure and a short description of major sources for the information required at that level. Prior to the ‘filter’ approach presented below, the identity and nomenclature of each taxon was verified using FishBase (www.fishbase.org) and other sources, and the English common names and scientific names were updated. Filter 1: FAO Area The United Nations Food and Agriculture Organization (FAO) has divided the world’s oceans into 18 areas for statistical reporting purposes (Figure 1). Information on the occurrence of commercial taxa within these areas is available primarily through: (a) FAO publications and the FAO website (www.fao.org) and (b) FishBase. Figures 2a and 3a illustrate FAO area occurrence of Silver hake and Florida pompano respectively. Filter 2: Latitudinal range The second filter applied in this process is latitudinal ranges. Charles Darwin, after reviewing literature on the distribution of marine organisms, concluded that “latitude is a more important element than longitude” (see Pauly 2004, p. 125, for the sources of this and the quote below). This does not mean, however, that longitude and other factors do not play a role in determining a taxon’s distribution. Still, in the following quote, Darwin illustrates how latitude provides the key to understanding the composition of certain fauna: “Sir J. Richardson says the Fish of the cooler temperate parts of the S. Hemisphere present a much stronger analogy to the fish of the same latitudes in the North, than do the strictly Arctic forms to the Antarctic.” Latitudinal range is defined as a taxon’s northernmost and southernmost latitudes of what is considered their ‘normal’ distribution range and can be found in FishBase for most fishes. For other fishes and invertebrates, latitudes were inferred from the latitudinal range of countries that reported them, and/or from occurrence records in the Ocean Biogeographic Information System website (OBIS; www.iobis.org). A further refinement of a taxon’s latitude range can be defined by its relative occurrence throughout its latitudinal range. From first principles, a taxon can be assumed to be most abundant at the center of its range (McCall, 1990). In cases of distributions confined to either of the two hemispheres, this is approximated by a symmetrical triangular distribution peaking at the mean of the northernmost and southernmost latitudes. For distributions that straddle the equator, it is assumed that a taxon’s range can be broken into three parts – the outer two thirds and the inner or middle third. If the equator falls within one of the outer thirds of the latitudinal range, then the abundance is assumed to be the same as above, and thus the symmetrical triangular distribution can be applied. If, however, the equator falls in the middle third of the range, then the abundance distribution is assumed to be flat in the middle third and decreasing to the poles for the remainder of the distributions range. Figures 2b and 3b illustrate the result of the FAO and Latitudinal filter combined. Both the Silver hake and the Florida pompano follow the symmetrical triangular distribution as noted above. Fishes in Databases and Ecosystems, Palomares, M.L.D., Stergiou, K.I., Pauly, D. 29