Experiencia auténtica del iBT Writing con barra de progreso animada
Task 1: Integrated Writing
📋 Formato de esta Tarea
📖
Reading
3 min
→
🎧
Audio Lecture
2.5 min
→
✍️
Escribir Ensayo
20 min
🎧 CON AUDIO - 150-225 palabras⏱️ Total: ~20 min
0%
Listo para comenzar el examen
🎯
Listo
📖
Reading
3 min
🎧
Audio
2.5 min
✍️
Escribiendo
20 min
✅
Completado
🎯 Presiona para comenzar el examen
El examen seguirá automáticamente la secuencia del TOEFL iBT Writing.
📖 Reading Passage
⏱️ Reading: 3:00
Sea Otter Population Decline
Sea otters are a small mammal that lives in the waters along North America's west coast from California to Alaska. A few years ago some of the sea otter populations off of the Alaskan coast started to decline rapidly and raised several concerns because of their important role in the coastal ecosystem.
Experts began investigating and came up with two possible explanations. One explanation was environmental pollution and the second was attacks by predators. At first it seemed as if the pollution was the most likely cause for the population decline. One reason pollution was more likely was because of the known pollution sources along the Alaskan coast such as oil rigs. Also water samples taken in the area showed increased levels of chemicals that could decrease the otters' immune systems and indirectly result in their deaths.
Another thing that pointed to pollution as the culprit was the decline of other sea mammals such as seals in the same areas. This indicated that whatever was affecting the otters was also affecting the other sea mammals. Environmental pollution usually affects an entire ecosystem instead of just one species. Only predators that occurred in a large area, such as orcas (a large predatory whale), could cause the same effect, but they usually hunt larger prey.
Finally, scientists believed the pollution hypothesis would also explain the uneven pattern of otter decline. In some Alaskan locations the otter population declined greatly while other populations remained stable. Some experts suggested this could be explained by ocean currents, or other environmental factors, might have created uneven concentrations of pollutants along the coast.
🎧 Academic Lecture
⏱️ Audio: 2:30
📝 Transcripción (Solo para estudio - NO aparece en el examen real):
Professor: Ongoing investigations have shown that predation is the most likely cause of the sea otter decline after all. First, there is a lack of dead sea otters washing up on Alaskan beaches, which is not what you would expect from infections caused by pollution killing them off. However, the fact that dead sea otters are seldom found supports the predator hypothesis: if a predator kills an otter, then it is eaten right away and can't wash up on shore. Orcas prefer to hunt whales, but whales have essentially disappeared in that area due to human hunters. Since the whales are not as available, orcas have had to change their diet to what is available. Since only smaller sea animals are available, the orcas have probably started hunting those more and created the decline in all of the species mentioned in the passage. And finally, predation is a more likely reason for the uneven pattern of otter decline. Otters in locations that are more accessible to orcas are more likely to be hunted. This is supported by the stable population of otters in shallow, rocky locations where orcas can't access.
📝 Pregunta del Ensayo Integrado
⏱️ Writing: 20:00
Summarize the points made in the lecture, being sure to explain how they respond to the specific points made in the reading passage.
Palabras: 0
📝 Respuesta Modelo (Banda 5/5)
The lecture challenges the reading's argument that pollution is the primary cause of sea otter population decline, instead presenting evidence that predation by orcas is the most likely explanation. First, the professor disputes the pollution theory by pointing to the lack of dead sea otters washing up on Alaskan beaches. According to the lecture, if pollution were killing the otters through infections or immune system damage as suggested in the reading, we would expect to find dead otters on the shore. However, the absence of otter carcasses actually supports the predation hypothesis, since predators would consume their prey immediately, preventing the bodies from washing ashore. Second, while the reading suggests that orcas typically hunt larger prey and wouldn't target otters, the professor explains that orcas have been forced to change their hunting patterns. The lecture reveals that whales, the orcas' preferred prey, have essentially disappeared from the area due to human hunting activities. With their primary food source unavailable, orcas have adapted by hunting smaller marine animals that are accessible, including sea otters. Finally, regarding the uneven pattern of otter decline across different Alaskan locations, the professor offers a more compelling explanation than the reading's pollution theory. Rather than attributing the pattern to ocean currents distributing pollutants unevenly, the lecture argues that predation better explains these geographical differences.