Harold Carl Otto Loesch (October 3, 1926 – May 12, 2011) was a marine biologist and oceanographer who is credited with being the first to examine the Mobile Bay jubilee in an academic journal[1] (Ecology).paper Much of his career was as an academic holding a professorship in the Department of Marine Sciences at Louisiana State University, though he also spent many years working for the United Nations agencies UNESCO and FAO to develop fisheries in newly industrialized countries.

During this time he studied shrimp fisheries in nearby Barataria Bay in association with the National Science Foundation Sea Grant Development Office.

He also held the titles of visiting professor in both the Organization of American States Marine Sciences Program in Guayaquil, Ecuador, and at The School for Field Studies Marine Ecology program at South Caicos Island in the British West Indies.

From 1960 to 1968 Loesch worked as a shrimp biologist and fisheries officer for the Food and Agriculture Organization of the United Nations in Guatemala City, Guatemala, Guayaquil, Ecuador and Tegucigalpa, and La Ceiba, Honduras.

He served as lead biologist for the United Nations Development Programme at Monterrey Institute of Technology and Higher Education and at the National Autonomous University of Mexico Marine Station in Ciudad del Carmen, Mexico from 1976 to 1980.