John D. Karlsson

It is with profound sadness that we report the death of John David Karlsson of Hope Valley and Little Compton Rhode Island on June 18th, 2025. He was 82. John died in Home Hospice care after suffering from an infection and complications from heart valve surgery in April of 2023 and kidney failure from immunotherapy treatment for cancer.

John was born in Santa Monica, California on February 22, 1943 and lived there until GTE moved the family to San Angelo, Texas where John developed his interest in reptiles and amphibians. Later the family moved to New York City with John graduating from Roosevelt High School in Yonkers and earning a varsity letter in riflery. He then attended and graduated from Grinnell College in Iowa with a degree in Biology/Herpetology.

John was a self taught five string banjo player and played Blue Grass and Old Timey music with various groups through college and later in Washington Square, NYC with many of the famous folk musicians of the time. Later after settling in Jamestown, RI he could be heard playing on Banjo nights in town or on the stern of the Tallship Rose in Newport Harbor.

After a short stint in medical research at Sloan Kettering, John took a position as a research marine fisheries biologist in Rhode Island studying and laboratory rearing Bay Scallops for transplantation to the field. The transplanted scallops grew to be harvested, but never produced a sustaining population in the field. Suspecting parasitic interference of reproduction, John traveled to Oxford Maryland to learn bivalve histology from NOAA Histologist Austin Farley. Slides produced from local scallops showed a parasite destroying the egg masses in the scallops explaining their inability to reproduce in the field. Later that parasite was named for him as Perkinsus karlssoni and can be found in all the warmer waters of southern New England.

John was also a Land Rover enthusiast, owning several during his life.

He enjoyed off-roading with various Rover clubs and showing his scruffy

Rovers at the British By the Sea Shows at Harkness Park. CT.

John and his wife were the owners of Sakonnet PWDs Kennel and were recognized as AKC breeders of Merit producing many award winning Portuguese Water Dogs in both conformation and performance venues. Today, friends in the breed continue to breed their healthy line of dogs.

John was not a religious man, so there will be no service. The family asks that you make a toast to his wonderful, musical, humorous, and scientifically productive life with a stiff dark rum drink or a Guinness and contribute in his memory to the Sakonnet Preservation Association P.O. Box 945, Little Compton, RI 02837 or the Portuguese Water Dog Foundation 500 Westover DR 30318 Sanford, NC 27330.

John is survived by his wife, Mary Woodcock Karlsson, his son Erik Anders Karlsson and numerous cousins in Sweden.