Complex sentence: However, this demand for sea sponges has seen catch rates peak and in 2003 the demand for bath sponges was 2,127 tonnes, with global production from harvesting only meeting a quarter of that amount.
Split into simpler sentences: However, this demand for sea sponges has seen catch rates reach maximum levels. In 2003 the demand for bath sponges was 2,127 tones, with global production from harvesting facilitating only a quarter of that amount.