• Question: How will polution affect species reproduction?

    Asked by naylahh5106 to Allan, Angela, Diva, Harriet, Nathan on 29 Jun 2012.
    • Photo: Nathan Langford

      Nathan Langford answered on 29 Jun 2012:

      Hi naylahh5106,

      Very cool question – I think the others will probably be better at answering this than me, but I’ll tell you one way that pollution will affect species reproduction, although you might not normally think of it in this way.

      One of the effects of pollution over many years is to slowly raise global water temperature, even if it’s only been by one or two degrees so far, on average. However, it turns out that is already enough to do cause real damage to the Great Barrier Reef.

      Did you know that coral is actually a living animal? Well, it turns out that coral needs quite a specific temperature to be able to survive well. If it gets too hot, then you get something called “coral bleaching”. I’m sure Diva could tell you much more about this, but basically it means that the coral cannot survive, reproduce and spread in the proper way in the warmer temperature, so the reefs gradually die back.

      Oh, another way that pollution can affect species reproduction is in water pollution in rivers. In many river systems, mangroves line the river banks and these mangroves are an incredibly important part of the whole river ecosystem. If the rivers get more developed, more polluted or even just more salty, this can start killing off the mangroves. But these mangroves are the vital breeding ground for a lot of the fish and marine life in the river. Without the mangroves, the populations of animals that live in the river start to die away and this can lead to problems for other animals which may use the river for food, or even just clean water, because once the natural river ecosystem starts dying, sometimes the water starts to become dangerous too.

      Hope that helps…
      Cheers,
      Nathan.

    • Photo: Diva Amon

      Diva Amon answered on 3 Jul 2012:

      Hi naylahh5106,

      This is great question which has lots of answers. Nathan’s answer was great! I could probably write pages and pages to you about it if I had more time but for now the short answer is that pollution never affects a species reproduction positively.

      Animals use their energy for two main functions: growing/survival or reproduction. What tends to happen in a polluted environment is that an animal becomes stressed. This triggers the animal to direct its energy to survival and away from reproduction. So pollution can cause a species’s reproduction to decrease.

      A very specific and famous example of pollution affecting an animals reproduction is from a chemical called tributyltin or TBT. TBT used to be used to paint the underside of boats and ships to prevent animals growing (fouling). It was discovered that this chemical is extremely harmful to marine organisms, specifically dog whelks. In case you don’t know what a dog whelk is, here is a photo:

      TBT causes the female snails to grow male sex organs like a penis. The penis then blocks the normal female organs so she cannot release her eggs. This causes the females to become sterile (not reproduce anymore) or in the worst cases, causes the eggs to build up within the female until she explodes and dies. The fact that the female is now either sterile or dead means that no more babies can be born and this affects overall population numbers causing them to drop.

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