{"id":489070,"date":"2026-06-12T10:18:10","date_gmt":"2026-06-12T10:18:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/489070\/"},"modified":"2026-06-12T10:18:10","modified_gmt":"2026-06-12T10:18:10","slug":"climate-change-is-causing-fish-to-move-to-cooler-water-but-what-if-their-escape-route-is-blocked","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/489070\/","title":{"rendered":"Climate change is causing fish to move to cooler water. But what if their escape route is blocked?"},"content":{"rendered":"

Around the world, ocean warming<\/a> is causing fish to move polewards in search of cooler water. <\/p>\n

But what if you\u2019re a tiny prawn, barramundi or rare sawfish in a northern Australian gulf and your exit southwards is blocked by land? To date, there\u2019s been a global gap in understanding how shallow tropical gulfs and bays are responding to climate change. <\/p>\n

These marine environments are vital for nature, fisheries and coastal communities. However, their conditions are becoming more extreme and variable due to cumulative climate change. Species are riding an environmental roller coaster, with the rapid changes hindering their recovery. <\/p>\n

Some of the world\u2019s most populous countries \u2013 and unique species \u2013 are in the tropics. Lessons from remote northern Australia can prove insightful. <\/p>\n

Our new research<\/a> focuses on these unique Australian ecosystems and highlights their importance and complexity. It takes into account land barriers, the monsoonal climate, influence of cyclones and massive variability in sea levels. <\/p>\n

Northern Australian seas are unique<\/p>\n

To help unravel the complex dynamics of these systems, our team drew on the CSIRO\u2019s 50-year history of research in northern Australia, focused on the Gulf of Carpentaria, Joseph Bonaparte Gulf and Torres Strait. Northern Australia has many seagrasses and mangroves, and is a stronghold for threatened species such as sawfish, dugongs, turtles and the snubfin dolphin. <\/p>\n

We analysed climate influences on popular fishing species, such barramundi, mud crabs and lobsters, as well as Australia\u2019s largest and most valuable prawn fishery, the Northern Prawn Fishery<\/a>. And we discovered ocean temperature isn\u2019t the only important indicator of climate change. <\/p>\n

Our research showed these marine systems are influenced by compounding climate events in complex ways, which can be simplified into four primary factors to explain how, why and when species are affected. <\/p>\n

We found combinations of extreme temperatures, exposure to dehydration, cloudiness in the water (turbidity) and hydrologic disconnection \u2013 the restriction or changes to the natural movement of water \u2013 combined to bolster some populations while devastating others. These patterns of change are largely influenced by El Ni\u00f1o or La Ni\u00f1a<\/a> weather events.<\/p>\n

Species are riding more extreme climate rollercoasters, with steeper and larger changes in the marine environment hindering their recovery. A good example is the brown tiger prawn.<\/p>\n

The Goldilocks prawn<\/p>\n

The original impetus for our research<\/a> was to understand why present-day brown tiger prawn populations in northern Australia had not bounced back to levels seen before the turn of the century, despite reduced fishing. This region is the only place they exist. <\/p>\n

We called them the \u201cGoldilocks\u201d prawns because they like ocean conditions that are just right \u2013 not too hot or too cold. Furthermore, earlier research<\/a> showed juvenile brown tiger prawns are very fussy about the kinds of seagrass they use for shelter and food. <\/p>\n

Our research found strong evidence of a major step-change in physical conditions around 1998 or 1999. Specifically, there were more La Ni\u00f1as over the past two decades, higher than average freshwater flows, including from the Roper River<\/a>, and increased cyclone intensity. <\/p>\n

Cyclones cause massive seagrass damage, while sediment from flooding rivers limits seagrass growth. This means reduced nursery habitat for the brown tiger prawn already under pressure from rising temperatures. Our modelling found a sustained decrease in brown tiger prawns connected to a shift in climate patterns.<\/p>\n

By contrast, the more robust grooved tiger prawns were not similarly affected, and common and redleg banana prawns thrived in response to good river flows. In fact, Redleg banana prawns<\/a>, sawfish and mangroves<\/a> are at risk during El Ni\u00f1o periods, when dry weather and lowered sea levels disrupt the river-ocean connections they rely on.<\/p>\n

\"\"<\/p>\n

Grooved tiger prawns (top right) look similar, but brown tiger prawns (bottom prawn and two facing right) have fussier habitat requirements.
\n Rob Kenyon\/CSIRO<\/p>\n

Why this matters<\/p>\n

Climate change is playing out differently in northern Australia to the rest of the country. This new research will help us anticipate, prepare for and respond to compound climate events \u2013 when multiple weather or climate conditions interact with severe environmental consequences. <\/p>\n

For example, fisheries could switch between tiger and banana prawns depending on environmental conditions. Conservation teams could benefit from knowing in advance how extreme climate events threaten species such as the endangered largetooth sawfish<\/a>. <\/p>\n

Globally, better waterway management is needed, because taking too much water out of river systems<\/a> threatens downstream ecosystems and marine livelihoods.<\/p>\n

An extreme El Ni\u00f1o<\/a> is forecast for later this year. Our work offers insights into its potential impacts across these marine environments and helps ecosystem and fisheries managers prepare. <\/p>\n

\"A<\/a><\/p>\n

CSIRO researchers studied mangroves and collected seagrass samples in Australia\u2019s Gulf of Carpentaria to help understand how compound climate events are influencing tropical ecosystems.
\n Rob Kenyon\/CSIRO<\/p>\n","protected":false},"excerpt":{"rendered":"Around the world, ocean warming is causing fish to move polewards in search of cooler water. But what…\n","protected":false},"author":2,"featured_media":489071,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[242,85,46,141],"class_list":["post-489070","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-environment","tag-il","tag-israel","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/489070","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=489070"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/489070\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/489071"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=489070"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=489070"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=489070"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}