Ian Hewson

Ian Hewson is an Australian American biological oceanographer and marine ecologist who is a professor of microbiology at Cornell University. He leads the Cornell Marine Mass Mortality Laboratory, where he studies the drives of marine mass mortalities. He was leader of diversity, equity, and inclusion for the Department of Microbiology.

Early life and education
Hewson was born in Singapore. He went to high school at Canberra Grammar School. He was an undergraduate student at the University of Queensland, where he studied botany and marine science. His honours research considered benthic microalgae. He moved to the University of Southern California for his doctoral research, where he worked on marine environmental biology. His doctoral research explored the impact of viruses on the composition of bacterial communities. During his PhD, he mapped the biogeography of taxa around the ocean. He then moved to the University of California, Santa Cruz to work on nitrogen fixing marine bacteria.

Research and career
In 2009, Hewson joined the Department of Microbiology at Cornell University. He has focused on aquatic virology, and how viruses influence keystone taxa. His research makes use of field surveys, laboratory analysis and computational simulation to understand marine mass mortalities.

Hewson has studied single-stranded DNA viruses and looked to understand their role in disease. He has studied sea star wasting disease (SSWD), a condition that impacted starfish from Alaska to Baja California. He looked to understand how viral infection impacts the microbiome of sea stars, and how sea star-associated densovirus (SSaDV) caused SSWD symptoms. He found that SSadV did not always correlate with SSWD, and that the wasting would be better known as Asteroid Idiopathic Wasting Syndrome. He explained that warmer oceans result in the production of excess organic material, which allows bacteria to thrive. This depletes the levels of oxygen available for starfish, which results in puffiness and discolouration.

In 2022, Hewson started studying why sea urchins in the Caribbean were becoming unwell. He took samples from healthy and unhealthy sea urchins, and showed that the sick sea urchins had traces of the parasite Philaster apodigitiformis.

Personal life
Hewson is gay and a member of 500 Queer Scientists. He plays ice hockey and competed in the 2017 Madison Gay Hockey Association tournament. He is an avid swimmer.