Transgenerational marking of freshwater fishes with enriched stable isotopes: a tool for fisheries management and research.

A promising new method of marking larval freshwater fishes with enriched stable isotopes by means of injecting the maternal parent with the marking agent was investigated. The (138)Ba:(137)Ba ratios in the otoliths of larval golden perch Macquaria ambigua were compared to determine the effect of injecting female broodstock with different dosages of enriched (137)Ba at various times before spawning. There was 100% mark success in the progeny of fish injected with 20 microg g(-1) of enriched (137)Ba 24 h before inducing spawning with hormones and 40 microg g(-1) administered at the same time as inducement of spawning. Injection of 40 microg g(-1) enriched (137)Ba 21 days before spawning resulted in only 81% mark success and suggests rapid elimination of barium in M. ambigua. Injection with enriched (137)Ba did not significantly affect the fertilization rate, number of fertilized eggs or hatching rate compared with long-term hatchery records. These results suggest that transgenerational marking is an effective and affordable means of mass-marking larval fishes. Thousands of larval fishes can be permanently marked with a unique artificial isotopic mark via a single injection into the maternal parent, thus avoiding the handling of individual fishes or having to deal with chemical baths. Because no single mark or tagging method is suitable for all situations, transgenerational marking with enriched stable isotopes provides another method for researchers and managers to discriminate both hatchery-reared and wild fishes.

Roe v. Wade. Into the next millennium.

PIP: In order to take the fight for reproductive rights into the next millennium, women in the US must be reminded of what life was like for women when contraception and abortion were illegal, and the silent majority of women who accept that abortion is a private decision must be marshalled to express their views politically. In the US, abortion was allowed until the mid- to late-1800s when Protestant leaders feared that Protestant births were being outnumbered by births to Irish Roman Catholic immigrants. There was only minimal organized opposition to abortion during the period when it was illegal and millions of women were dying as a result. An estimated 30,000 women died each year of illegal abortion in the US, and by the 1960s, illegal abortion was the greatest killer of women of reproductive age. Organized medicine, which witnessed these tragedies, never rallied to assure women quality reproductive health care. In fact, one of the first projects of the American Medical Association (AMA) was an anti-abortion campaign designed to put competitors out of business. The AMA waited until 1937 to endorse contraception and until the late 1960s to make efforts to legalize abortion. In 1997, the AMA again abandoned women by supporting the ban on late-term abortions. Pro-choice forces should prioritize the promotion of technological advances that will allow women to control conception and abortion. The means of achieving medical abortion and emergency contraception should be available in every physician's office and should be covered by every health insurance scheme. Reproductive health advocates must also work to inspire honesty about sex and sexuality in our sexually-obsessed, sexually-repressed society. Sex education in Denmark has nearly obliterated adolescent pregnancy and led to an 80% decline in the abortion rate over 30 years. In the US, nearly half of women have an abortion, and anti-abortion advocates should face the reality that their wives, daughters, mothers, and sisters have been affected by the right to choose. It is time to claim the moral high ground in the effort to secure safe, quality reproductive health care for all women.^ieng