Evaluating and understanding biodiversity in marine ecosystems are both necessary and challenging for conservation. This paper compiles and summarizes current knowledge of the diversity of marine taxa in Canada's three oceans while recognizing that this compilation is incomplete and will change in the future. That Canada has the longest coastline in the world and incorporates distinctly different biogeographic provinces and ecoregions (e.g., temperate through ice-covered areas) constrains this analysis. The taxonomic groups presented here include microbes, phytoplankton, macroalgae, zooplankton, benthic infauna, fishes, and marine mammals. The minimum number of species or taxa compiled here is 15,988 for the three Canadian oceans. However, this number clearly underestimates in several ways the total number of taxa present. First, there are significant gaps in the published literature. Second, the diversity of many habitats has not been compiled for all taxonomic groups (e.g., intertidal rocky shores, deep sea), and data compilations are based on short-term, directed research programs or longer-term monitoring activities with limited spatial resolution. Third, the biodiversity of large organisms is well known, but this is not true of smaller organisms. Finally, the greatest constraint on this summary is the willingness and capacity of those who collected the data to make it available to those interested in biodiversity meta-analyses. Confirmation of identities and intercomparison of studies are also constrained by the disturbing rate of decline in the number of taxonomists and systematists specializing on marine taxa in Canada. This decline is mostly the result of retirements of current specialists and to a lack of training and employment opportunities for new ones. Considering the difficulties encountered in compiling an overview of biogeographic data and the diversity of species or taxa in Canada's three oceans, this synthesis is intended to serve as a biodiversity baseline for a new program on marine biodiversity, the Canadian Healthy Ocean Network. A major effort needs to be undertaken to establish a complete baseline of Canadian marine biodiversity of all taxonomic groups, especially if we are to understand and conserve this part of Canada's natural heritage.

No abstract

Palladium phosphanesulfonate [R(2)P(C(6)H(4)-o-SO(3))PdMeL] catalysts permit the copolymerization of an exceptional large number of functional olefins with ethylene. However, these catalysts usually have reduced activity. We here have conducted a systematic study on the influence of the phosphane substituent, R, on activity and molecular weight. Phosphanes with strong σ-donating character are shown to lead to the most active catalysts. Thus, the catalyst based on phosphane bis-tert-butyl-phosphanyl-benzenesulfonic acid (R=tBu) exhibits unprecedented high activity, rapidly polymerizing ethylene at room temperature to yield a linear polymer of high molecular weight (M(w)=116,000 g mol(-1)). The influence of the R group on the catalyst ability to incorporate methyl acrylate is also investigated.

b S Supporting Information T he physical properties of polyethylene (PE) can be drastically altered by careful manipulation of its microstructure and particularly by controlling the length and distribution of alkyl branches along the chain. Instead of alkyl chains, it would be desirable to introduce low amounts of polar groups because they are expected to greatly impact the toughness, flexibility, crack resistance, gas permeability, miscibility, adhesion, and paintability of PE. 1 These copolymers are also of prime importance for the formation of nanocomposites since the presence of polar groups enhances compatibility between the polymeric matrix and the dispersed charge. 2 However, catalytic polymerization of readily available polar monomers is still one of the major challenges in the field of olefin polymerization. 3 Among all polar monomers, those bearing easily functionalized groups such as carboxylic acid and anhydrides would offer a unique opportunity for the direct preparation of functional PEs.Polymers bearing anhydride functionalities can be prepared by reactive extrusion of molten PE in the presence of maleic anhydride (MA) and a radical initiator. This radical process not only grafts the anhydride as a pendant group but also generates several undesirable side reactions such as chain scission and chain branching. 4 Radical copolymerization of ethylene with acrylic acid (AA) or methacrylic acid yields ionomers, 5 that is to say, thermoplastics containing acid groups converted to metal salts which act as physical cross-links. These commercially important polymers are used in a variety of applications, including orthodontics and prosthetics, as films, adhesive layers in foil/ paper containers, and as constituents of items such as golf balls and bowling pins. We recently demonstrated that linear copolymers of ethylene and AA exhibit higher crystallinity and melting points than their branched counterparts. 6 Furthermore, in water they self-assemble into thermosensitive nanoparticles. These copolymers were prepared by catalytic copolymerization of ethylene with tert-butyl acrylate followed by deprotection of the ester. Clearly, it would be advantageous to prepare these copolymers by direct copolymerization with AA.We have probed the preparation of functional PE by catalytic copolymerization of ethylene with AA, MA, and carbic anhydride (CA, 5-norbornene-endo-2,3-dicarboxylic anhydride) using Pdbased well-defined catalysts 1 or 2 (Scheme 1). The choice of these catalysts is motivated by the fact that Pd phosphine aryl sulfonates allow for the copolymerization of a wide range of monomers, such as acrylonitrile, 7 vinyl ethers, 8 vinyl esters, 9 vinyl fluoride, 10 acrylates, 11-14 norbornenes, 15,16 styrenes, 17 vinyl ketones, 17 acrylamides, 18 N-vinylpyrrolidone, 18 vinyl sulfones, 19

(Arylsulfonyl)phosphane ligands, o-Ar 2 PC 6 H 4 SO 3 H in which Ar is phenyl (Ph), naphthyl (Np), phenanthryl (Pa), or anthracenyl (An) were prepared. These bulky phosphanes were used to generate phosphanepalladium complexes [(o-Ar 2 -PC 6 H 4 SO 3 )PdMe(pyridine)]. These complexes catalyze eth-